Merge tag 'OTP-19.0' into sverker/19/binary_to_atom-utf8-crash/ERL-474/OTP-14590

35 files changed, 3917 insertions, 2206 deletions

diff --git a/lib/mnesia/src/Makefile b/lib/mnesia/src/Makefile
index ac38fa05ef..08a00e6aba 100644
--- a/lib/mnesia/src/Makefile
+++ b/lib/mnesia/src/Makefile
@@ -1,18 +1,19 @@
 #
 # %CopyrightBegin%
 # 
-# Copyright Ericsson AB 1996-2013. All Rights Reserved.
+# Copyright Ericsson AB 1996-2016. All Rights Reserved.
 # 
-# The contents of this file are subject to the Erlang Public License,
-# Version 1.1, (the "License"); you may not use this file except in
-# compliance with the License. You should have received a copy of the
-# Erlang Public License along with this software. If not, it can be
-# retrieved online at http://www.erlang.org/.
-# 
-# Software distributed under the License is distributed on an "AS IS"
-# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-# the License for the specific language governing rights and limitations
-# under the License.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
 # 
 # %CopyrightEnd%
 #
@@ -42,6 +43,7 @@ RELSYSDIR = $(RELEASE_PATH)/lib/mnesia-$(VSN)
 # ----------------------------------------------------
 MODULES= \
 	mnesia \
+	mnesia_backend_type \
 	mnesia_backup \
 	mnesia_bup \
 	mnesia_checkpoint \
@@ -49,6 +51,7 @@ MODULES= \
 	mnesia_controller \
 	mnesia_dumper\
 	mnesia_event \
+	mnesia_ext_sup \
 	mnesia_frag \
 	mnesia_frag_hash \
 	mnesia_frag_old_hash \
diff --git a/lib/mnesia/src/mnesia.app.src b/lib/mnesia/src/mnesia.app.src
index 3715488ec2..006ad4bac1 100644
--- a/lib/mnesia/src/mnesia.app.src
+++ b/lib/mnesia/src/mnesia.app.src
@@ -3,6 +3,7 @@
   {vsn, "%VSN%"},
   {modules, [
 	     mnesia, 
+	     mnesia_backend_type,
 	     mnesia_backup, 
 	     mnesia_bup, 
 	     mnesia_checkpoint, 
@@ -10,6 +11,7 @@
 	     mnesia_controller,
 	     mnesia_dumper, 
 	     mnesia_event, 
+	     mnesia_ext_sup,
 	     mnesia_frag, 
 	     mnesia_frag_hash, 
              mnesia_frag_old_hash,
@@ -47,6 +49,7 @@
 		mnesia_tm
 	       ]},
   {applications, [kernel, stdlib]},
-  {mod, {mnesia_sup, []}}]}.
+  {mod, {mnesia_sup, []}},
+  {runtime_dependencies, ["stdlib-2.0","kernel-3.0","erts-7.0"]}]}.
 
 
diff --git a/lib/mnesia/src/mnesia.appup.src b/lib/mnesia/src/mnesia.appup.src
index 355aafb215..c245299740 100644
--- a/lib/mnesia/src/mnesia.appup.src
+++ b/lib/mnesia/src/mnesia.appup.src
@@ -1,22 +1,16 @@
 %% -*- erlang -*-
 {"%VSN%",
  [
-  {"4.7.1",  [{restart_application, mnesia}]},
-  {"4.7",  [{restart_application, mnesia}]},
-  {"4.6",  [{restart_application, mnesia}]},
-  {"4.5.1",  [{restart_application, mnesia}]},
-  {"4.5",    [{restart_application, mnesia}]},
+  {<<"4\\.1[0-9].*">>, [{restart_application, mnesia}]},
+  {<<"4\\.[5-9].*">>, [{restart_application, mnesia}]},
   {"4.4.19", [{restart_application, mnesia}]},
   {"4.4.18", [{restart_application, mnesia}]},
   {"4.4.17", [{restart_application, mnesia}]},
   {"4.4.16", [{restart_application, mnesia}]}
  ],
  [
-  {"4.7.1",  [{restart_application, mnesia}]},
-  {"4.7",  [{restart_application, mnesia}]},
-  {"4.6",  [{restart_application, mnesia}]},
-  {"4.5.1",  [{restart_application, mnesia}]},
-  {"4.5",    [{restart_application, mnesia}]},
+  {<<"4\\.1[0-9].*">>, [{restart_application, mnesia}]},
+  {<<"4\\.[5-9].*">>, [{restart_application, mnesia}]},
   {"4.4.19", [{restart_application, mnesia}]},
   {"4.4.18", [{restart_application, mnesia}]},
   {"4.4.17", [{restart_application, mnesia}]},
diff --git a/lib/mnesia/src/mnesia.erl b/lib/mnesia/src/mnesia.erl
index 70466d10d7..9586adbf93 100644
--- a/lib/mnesia/src/mnesia.erl
+++ b/lib/mnesia/src/mnesia.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -81,7 +82,8 @@
 	 system_info/0,                      % Not for public use
 
 	 %% Database mgt
-	 create_schema/1, delete_schema/1,
+	 create_schema/1, create_schema/2, delete_schema/1,
+         add_backend_type/2,
 	 backup/1, backup/2, traverse_backup/4, traverse_backup/6,
 	 install_fallback/1, install_fallback/2,
 	 uninstall_fallback/0, uninstall_fallback/1,
@@ -104,7 +106,8 @@
 	 set_master_nodes/1, set_master_nodes/2,
 
 	 %% Misc admin
-	 dump_log/0, subscribe/1, unsubscribe/1, report_event/1,
+	 dump_log/0, sync_log/0,
+	 subscribe/1, unsubscribe/1, report_event/1,
 
 	 %% Snmp
 	 snmp_open_table/2, snmp_close_table/1,
@@ -144,7 +147,7 @@
 %% Local function in order to avoid external function call
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason);
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
 	Value -> Value
     end.
 
@@ -195,6 +198,9 @@ e_has_var(X, Pos) ->
 %% Start and stop
 
 start() ->
+    start([]).
+
+start_() ->
     {Time , Res} =  timer:tc(application, start, [?APPLICATION, temporary]),
 
     Secs = Time div 1000000,
@@ -230,7 +236,7 @@ patched_start([{Env, Val} | Tail]) when is_atom(Env) ->
 patched_start([Head | _]) ->
     {error, {bad_type, Head}};
 patched_start([]) ->
-    start().
+    start_().
 
 stop() ->
     case application:stop(?APPLICATION) of
@@ -295,6 +301,7 @@ ms() ->
 
      %% Keep these last in the list, so
      %% mnesia_sup kills these last
+     mnesia_ext_sup,
      mnesia_monitor,
      mnesia_event
     ].
@@ -305,6 +312,8 @@ ms() ->
 
 -spec abort(_) -> no_return().
 
+abort(Reason = {aborted, _}) ->
+    exit(Reason);
 abort(Reason) ->
     exit({aborted, Reason}).
 
@@ -552,22 +561,16 @@ write(_Tid, _Ts, Tab, Val, LockKind) ->
     abort({bad_type, Tab, Val, LockKind}).
 
 write_to_store(Tab, Store, Oid, Val) ->
-    case ?catch_val({Tab, record_validation}) of
-	{RecName, Arity, Type}
-	  when tuple_size(Val) == Arity, RecName == element(1, Val) ->
-	    case Type of
-		bag ->
-		    ?ets_insert(Store, {Oid, Val, write});
-		_  ->
-		    ?ets_delete(Store, Oid),
-		    ?ets_insert(Store, {Oid, Val, write})
-	    end,
-	    ok;
-	{'EXIT', _} ->
-	    abort({no_exists, Tab});
-	_ ->
-	    abort({bad_type, Val})
-    end.
+    {_, _, Type} = mnesia_lib:validate_record(Tab, Val),
+    Oid = {Tab, element(2, Val)},
+    case Type of
+	bag ->
+	    ?ets_insert(Store, {Oid, Val, write});
+	_  ->
+	    ?ets_delete(Store, Oid),
+	    ?ets_insert(Store, {Oid, Val, write})
+    end,
+    ok.
 
 delete({Tab, Key}) ->
     delete(Tab, Key, write);
@@ -806,7 +809,7 @@ next(Tid,Ts,Tab,Key)
 	tid ->
 	    lock_table(Tid, Ts, Tab, read),
 	    do_fixtable(Tab,Ts),
-	    New = (catch dirty_next(Tab,Key)),
+	    New = ?CATCH(dirty_next(Tab,Key)),
 	    stored_keys(Tab,New,Key,Ts,next,
 			val({Tab, setorbag}));
 	_Protocol ->
@@ -832,7 +835,7 @@ prev(Tid,Ts,Tab,Key)
 	tid ->
 	    lock_table(Tid, Ts, Tab, read),
 	    do_fixtable(Tab,Ts),
-	    New = (catch dirty_prev(Tab,Key)),
+	    New = ?CATCH(dirty_prev(Tab,Key)),
 	    stored_keys(Tab,New,Key,Ts,prev,
 			val({Tab, setorbag}));
 	_Protocol ->
@@ -964,7 +967,7 @@ foldl(Fun, Acc, Tab, LockKind) when is_function(Fun) ->
 
 foldl(ActivityId, Opaque, Fun, Acc, Tab, LockKind) ->
     {Type, Prev} = init_iteration(ActivityId, Opaque, Tab, LockKind),
-    Res = (catch do_foldl(ActivityId, Opaque, Tab, dirty_first(Tab), Fun, Acc, Type, Prev)),
+    Res = ?CATCH(do_foldl(ActivityId, Opaque, Tab, dirty_first(Tab), Fun, Acc, Type, Prev)),
     close_iteration(Res, Tab).
 
 do_foldl(A, O, Tab, '$end_of_table', Fun, RAcc, _Type, Stored) ->
@@ -1010,7 +1013,7 @@ foldr(ActivityId, Opaque, Fun, Acc, Tab, LockKind) ->
 	    true ->      %% Order doesn't matter for set and bag
 		TempPrev %% Keep the order so we can use ordsets:del_element
 	end,
-    Res = (catch do_foldr(ActivityId, Opaque, Tab, dirty_last(Tab), Fun, Acc, Type, Prev)),
+    Res = ?CATCH(do_foldr(ActivityId, Opaque, Tab, dirty_last(Tab), Fun, Acc, Type, Prev)),
     close_iteration(Res, Tab).
 
 do_foldr(A, O, Tab, '$end_of_table', Fun, RAcc, _Type, Stored) ->
@@ -1139,10 +1142,12 @@ match_object(_Tid, _Ts, Tab, Pat, _LockKind) ->
 
 add_written_match(S, Pat, Tab, Objs) ->
     Ops = find_ops(S, Tab, Pat),
-    add_match(Ops, Objs, val({Tab, setorbag})).
+    FixedRes = add_match(Ops, Objs, val({Tab, setorbag})),
+    MS = ets:match_spec_compile([{Pat, [], ['$_']}]),
+    ets:match_spec_run(FixedRes, MS).
 
 find_ops(S, Tab, Pat) ->
-    GetWritten = [{{{Tab, '_'}, Pat, write}, [], ['$_']},
+    GetWritten = [{{{Tab, '_'}, '_', write}, [], ['$_']},
 		  {{{Tab, '_'}, '_', delete}, [], ['$_']},
 		  {{{Tab, '_'}, Pat, delete_object}, [], ['$_']}],
     ets:select(S, GetWritten).
@@ -1542,16 +1547,9 @@ dirty_write(Tab, Val) ->
 
 do_dirty_write(SyncMode, Tab, Val)
   when is_atom(Tab), Tab /= schema, is_tuple(Val), tuple_size(Val) > 2 ->
-    case ?catch_val({Tab, record_validation}) of
-	{RecName, Arity, _Type}
-	when tuple_size(Val) == Arity, RecName == element(1, Val) ->
-	    Oid = {Tab, element(2, Val)},
-	    mnesia_tm:dirty(SyncMode, {Oid, Val, write});
-	{'EXIT', _} ->
-	    abort({no_exists, Tab});
-	_ ->
-	    abort({bad_type, Val})
-    end;
+    {_, _, _} = mnesia_lib:validate_record(Tab, Val),
+    Oid = {Tab, element(2, Val)},
+    mnesia_tm:dirty(SyncMode, {Oid, Val, write});
 do_dirty_write(_SyncMode, Tab, Val) ->
     abort({bad_type, Tab, Val}).
 
@@ -1603,8 +1601,8 @@ dirty_update_counter(Tab, Key, Incr) ->
 
 do_dirty_update_counter(SyncMode, Tab, Key, Incr)
   when is_atom(Tab), Tab /= schema, is_integer(Incr) ->
-    case ?catch_val({Tab, record_validation}) of
-	{RecName, 3, set} ->
+    case mnesia_lib:validate_key(Tab, Key) of
+	{RecName, 3, Type} when Type == set; Type == ordered_set ->
 	    Oid = {Tab, Key},
 	    mnesia_tm:dirty(SyncMode, {Oid, {RecName, Incr}, update_counter});
 	_ ->
@@ -1623,13 +1621,7 @@ dirty_read(Oid) ->
 
 dirty_read(Tab, Key)
   when is_atom(Tab), Tab /= schema ->
-%%    case catch ?ets_lookup(Tab, Key) of
-%%        {'EXIT', _} ->
-            %% Bad luck, we have to perform a real lookup
-            dirty_rpc(Tab, mnesia_lib, db_get, [Tab, Key]);
-%%        Val ->
-%%            Val
-%%    end;
+    dirty_rpc(Tab, mnesia_lib, db_get, [Tab, Key]);
 dirty_read(Tab, _Key) ->
     abort({bad_type, Tab}).
 
@@ -1808,7 +1800,7 @@ do_dirty_rpc(Tab, Node, M, F, Args) ->
 	{badrpc, Reason} ->
 	    timer:sleep(20), %% Do not be too eager, and can't use yield on SMP
 	    %% Sync with mnesia_monitor
-	    try sys:get_status(mnesia_monitor) catch _:_ -> ok end,
+	    _ = try sys:get_status(mnesia_monitor) catch _:_ -> ok end,
 	    case mnesia_controller:call({check_w2r, Node, Tab}) of % Sync
 		NewNode when NewNode =:= Node ->
 		    ErrorTag = mnesia_lib:dirty_rpc_error_tag(Reason),
@@ -1902,21 +1894,23 @@ any_table_info(Tab, _Item) ->
     abort({bad_type, Tab}).
 
 raw_table_info(Tab, Item) ->
-    case ?catch_val({Tab, storage_type}) of
-	ram_copies ->
-	    info_reply(catch ?ets_info(Tab, Item), Tab, Item);
-	disc_copies ->
-	    info_reply(catch ?ets_info(Tab, Item), Tab, Item);
-	disc_only_copies ->
-	    info_reply(catch dets:info(Tab, Item), Tab, Item);
-	unknown ->
-	    bad_info_reply(Tab, Item);
-	{'EXIT', _} ->
+    try
+	case ?ets_lookup_element(mnesia_gvar, {Tab, storage_type}, 2) of
+	    ram_copies ->
+		info_reply(?ets_info(Tab, Item), Tab, Item);
+	    disc_copies ->
+		info_reply(?ets_info(Tab, Item), Tab, Item);
+	    disc_only_copies ->
+		info_reply(dets:info(Tab, Item), Tab, Item);
+            {ext, Alias, Mod} ->
+                info_reply(catch Mod:info(Alias, Tab, Item), Tab, Item);
+	    unknown ->
+		bad_info_reply(Tab, Item)
+	end
+    catch error:_ ->
 	    bad_info_reply(Tab, Item)
     end.
 
-info_reply({'EXIT', _Reason}, Tab, Item) ->
-    bad_info_reply(Tab, Item);
 info_reply({error, _Reason}, Tab, Item) ->
     bad_info_reply(Tab, Item);
 info_reply(Val, _Tab, _Item) ->
@@ -2022,15 +2016,26 @@ display_tab_info() ->
     MasterTabs = mnesia_recover:get_master_node_tables(),
     io:format("master node tables = ~p~n", [lists:sort(MasterTabs)]),
 
+    case get_backend_types() of
+	[] -> ok;
+	Ts -> list_backend_types(Ts, "backend types      = ")
+    end,
+
+    case get_index_plugins() of
+	[] -> ok;
+	Ps -> list_index_plugins(Ps, "index plugins      = ")
+    end,
+
     Tabs = system_info(tables),
 
-    {Unknown, Ram, Disc, DiscOnly} =
-	lists:foldl(fun storage_count/2, {[], [], [], []}, Tabs),
+    {Unknown, Ram, Disc, DiscOnly, Ext} =
+	lists:foldl(fun storage_count/2, {[], [], [], [], []}, Tabs),
 
     io:format("remote             = ~p~n", [lists:sort(Unknown)]),
     io:format("ram_copies         = ~p~n", [lists:sort(Ram)]),
     io:format("disc_copies        = ~p~n", [lists:sort(Disc)]),
     io:format("disc_only_copies   = ~p~n", [lists:sort(DiscOnly)]),
+    [io:format("~-19s= ~p~n", [atom_to_list(A), Ts]) || {A,Ts} <- Ext],
 
     Rfoldl = fun(T, Acc) ->
 		     Rpat =
@@ -2038,7 +2043,7 @@ display_tab_info() ->
 			     read_only ->
 				 lists:sort([{A, read_only} || A <- val({T, active_replicas})]);
 			     read_write ->
-				 table_info(T, where_to_commit)
+				 [fix_wtc(W) || W <- table_info(T, where_to_commit)]
 			 end,
 		     case lists:keysearch(Rpat, 1, Acc) of
 			 {value, {_Rpat, Rtabs}} ->
@@ -2051,18 +2056,65 @@ display_tab_info() ->
     Rdisp = fun({Rpat, Rtabs}) -> io:format("~p = ~p~n", [Rpat, Rtabs]) end,
     lists:foreach(Rdisp, lists:sort(Repl)).
 
-storage_count(T, {U, R, D, DO}) ->
+get_backend_types() ->
+    case ?catch_val({schema, user_property, mnesia_backend_types}) of
+	{'EXIT', _} ->
+	    [];
+	{mnesia_backend_types, Ts} ->
+	    lists:sort(Ts)
+    end.
+
+get_index_plugins() ->
+    case ?catch_val({schema, user_property, mnesia_index_plugins}) of
+	{'EXIT', _} ->
+	    [];
+	{mnesia_index_plugins, Ps} ->
+	    lists:sort(Ps)
+    end.
+
+
+list_backend_types([{A,M} | T] = Ts, Legend) ->
+    Indent = [$\s || _ <- Legend],
+    W = integer_to_list(
+	  lists:foldl(fun({Alias,_}, Wa) ->
+			      erlang:max(Wa, length(atom_to_list(Alias)))
+		      end, 0, Ts)),
+    io:fwrite(Legend ++ "~-" ++ W ++ "s - ~s~n",
+	      [atom_to_list(A), atom_to_list(M)]),
+    [io:fwrite(Indent ++ "~-" ++ W ++ "s - ~s~n",
+	       [atom_to_list(A1), atom_to_list(M1)])
+     || {A1,M1} <- T].
+
+list_index_plugins([{N,M,F} | T] = Ps, Legend) ->
+    Indent = [$\s || _ <- Legend],
+    W = integer_to_list(
+	  lists:foldl(fun({N1,_,_}, Wa) ->
+			      erlang:max(Wa, length(pp_ix_name(N1)))
+		      end, 0, Ps)),
+    io:fwrite(Legend ++ "~-" ++ W ++ "s - ~s:~s~n",
+	      [pp_ix_name(N), atom_to_list(M), atom_to_list(F)]),
+    [io:fwrite(Indent ++ "~-" ++ W ++ "s - ~s:~s~n",
+	       [pp_ix_name(N1), atom_to_list(M1), atom_to_list(F1)])
+     || {N1,M1,F1} <- T].
+
+pp_ix_name(N) ->
+    lists:flatten(io_lib:fwrite("~w", [N])).
+
+fix_wtc({N, {ext,A,_}}) -> {N, A};
+fix_wtc({N,A}) when is_atom(A) -> {N, A}.
+
+storage_count(T, {U, R, D, DO, Ext}) ->
     case table_info(T, storage_type) of
-	unknown -> {[T | U], R, D, DO};
-	ram_copies -> {U, [T | R], D, DO};
-	disc_copies -> {U, R, [T | D], DO};
-	disc_only_copies -> {U, R, D, [T | DO]}
+	unknown -> {[T | U], R, D, DO, Ext};
+	ram_copies -> {U, [T | R], D, DO, Ext};
+	disc_copies -> {U, R, [T | D], DO, Ext};
+	disc_only_copies -> {U, R, D, [T | DO], Ext};
+        {ext, A, _} -> {U, R, D, DO, orddict:append(A, T, Ext)}
     end.
 
 system_info(Item) ->
-    case catch system_info2(Item) of
-	{'EXIT',Error} -> abort(Error);
-	Other -> Other
+    try system_info2(Item)
+    catch _:Error -> abort(Error)
     end.
 
 system_info2(all) ->
@@ -2072,9 +2124,10 @@ system_info2(all) ->
 system_info2(db_nodes) ->
     DiscNs = ?catch_val({schema, disc_copies}),
     RamNs = ?catch_val({schema, ram_copies}),
+    ExtNs = ?catch_val({schema, external_copies}),
     if
-	is_list(DiscNs), is_list(RamNs) ->
-	    DiscNs ++ RamNs;
+	is_list(DiscNs), is_list(RamNs), is_list(ExtNs) ->
+	    DiscNs ++ RamNs ++ ExtNs;
 	true ->
 	    case mnesia_schema:read_nodes() of
 		{ok, Nodes} -> Nodes;
@@ -2168,7 +2221,7 @@ system_info2(version) ->
 		    Version;
 		false ->
 		    %% Ensure that it does not match
-		    {mnesia_not_loaded, node(), now()}
+		    {mnesia_not_loaded, node(), erlang:timestamp()}
 	    end;
 	Version ->
 	    Version
@@ -2178,6 +2231,7 @@ system_info2(access_module) -> mnesia_monitor:get_env(access_module);
 system_info2(auto_repair) -> mnesia_monitor:get_env(auto_repair);
 system_info2(is_running) -> mnesia_lib:is_running();
 system_info2(backup_module) -> mnesia_monitor:get_env(backup_module);
+system_info2(backend_types) -> mnesia_schema:backend_types();
 system_info2(event_module) -> mnesia_monitor:get_env(event_module);
 system_info2(debug) -> mnesia_monitor:get_env(debug);
 system_info2(dump_log_load_regulation) -> mnesia_monitor:get_env(dump_log_load_regulation);
@@ -2214,6 +2268,7 @@ system_info_items(yes) ->
     [
      access_module,
      auto_repair,
+     backend_types,
      backup_module,
      checkpoints,
      db_nodes,
@@ -2307,11 +2362,17 @@ load_mnesia_or_abort() ->
 %% Database mgt
 
 create_schema(Ns) ->
-    mnesia_bup:create_schema(Ns).
+    create_schema(Ns, []).
+
+create_schema(Ns, Properties) ->
+    mnesia_bup:create_schema(Ns, Properties).
 
 delete_schema(Ns) ->
     mnesia_schema:delete_schema(Ns).
 
+add_backend_type(Alias, Module) ->
+    mnesia_schema:add_backend_type(Alias, Module).
+
 backup(Opaque) ->
     mnesia_log:backup(Opaque).
 
@@ -2378,11 +2439,10 @@ del_table_index(Tab, Ix) ->
     mnesia_schema:del_table_index(Tab, Ix).
 
 transform_table(Tab, Fun, NewA) ->
-    case catch val({Tab, record_name}) of
-	{'EXIT', Reason} ->
-	    mnesia:abort(Reason);
-	OldRN ->
-	    mnesia_schema:transform_table(Tab, Fun, NewA, OldRN)
+    try val({Tab, record_name}) of
+	OldRN -> mnesia_schema:transform_table(Tab, Fun, NewA, OldRN)
+    catch exit:Reason ->
+	    mnesia:abort(Reason)
     end.
 
 transform_table(Tab, Fun, NewA, NewRN) ->
@@ -2554,6 +2614,9 @@ set_master_nodes(Tab, Nodes) ->
 dump_log() ->
     mnesia_controller:sync_dump_log(user).
 
+sync_log() ->
+    mnesia_monitor:sync_log(latest_log).
+
 subscribe(What) ->
     mnesia_subscr:subscribe(self(), What).
 
@@ -2790,7 +2853,7 @@ pre_qlc(Opts, Tab) ->
     end.
 
 post_qlc(Tab) ->
-    case catch get(mnesia_activity_state) of
+    case get(mnesia_activity_state) of
 	{_,#tid{},_} -> ok;
 	_ ->
 	    case ?catch_val({Tab, setorbag}) of
diff --git a/lib/mnesia/src/mnesia.hrl b/lib/mnesia/src/mnesia.hrl
index 2855792646..0716dd87c8 100644
--- a/lib/mnesia/src/mnesia.hrl
+++ b/lib/mnesia/src/mnesia.hrl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -35,11 +36,16 @@
 -define(ets_last(Tab), ets:last(Tab)).
 -define(ets_prev(Tab, Key), ets:prev(Tab, Key)).
 -define(ets_slot(Tab, Pos), ets:slot(Tab, Pos)).
--define(ets_new_table(Tab, Props), ets:new(Tab, Props)).
+-define(ets_new_table(Tab, Props), _ = ets:new(Tab, Props)).
 -define(ets_delete_table(Tab), ets:delete(Tab)).
 -define(ets_fixtable(Tab, Bool), ets:fixtable(Tab, Bool)).
 
--define(catch_val(Var), (catch ?ets_lookup_element(mnesia_gvar, Var, 2))).
+
+-define(SAFE(OP), try (OP) catch error:_ -> ok end).
+-define(CATCH(OP), try (OP) catch _:_Reason -> {'EXIT', _Reason} end).
+
+-define(catch_val(Var), (try ?ets_lookup_element(mnesia_gvar, Var, 2)
+			 catch error:_ -> {'EXIT', {badarg, []}} end)).
 
 %% It's important that counter is first, since we compare tid's
 
@@ -53,13 +59,16 @@
          up_stores = [],  %% list of upper layer stores for nested trans
          level = 1}).     %% transaction level
 
--define(unique_cookie, {erlang:now(), node()}).
+-define(unique_cookie, {{erlang:monotonic_time() + erlang:time_offset(),
+			 erlang:unique_integer(),1},
+			node()}).
 
 -record(cstruct, {name,                            % Atom
 		  type = set,                      % set | bag
 		  ram_copies = [],                 % [Node]
 		  disc_copies = [],                % [Node]
 		  disc_only_copies = [],           % [Node]
+                  external_copies = [],            % [{{Alias,Mod},[Node]}]
 		  load_order = 0,                  % Integer
 		  access_mode = read_write,        % read_write | read_only
 		  majority = false,                % true | false
@@ -95,7 +104,7 @@
 		 ram_copies = [],
 		 disc_copies = [],
 		 disc_only_copies = [],
-		 snmp = [],
+		 ext = [],
 		 schema_ops = []
 		}).
 
diff --git a/lib/mnesia/src/mnesia_backend_type.erl b/lib/mnesia/src/mnesia_backend_type.erl
new file mode 100644
index 0000000000..4791b82a01
--- /dev/null
+++ b/lib/mnesia/src/mnesia_backend_type.erl
@@ -0,0 +1,115 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1996-2015. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+%%
+%% Behaviour definition for mnesia backend types.
+%%
+
+%%%header_doc_include
+
+-module(mnesia_backend_type).
+
+-export([behaviour_info/1]).
+
+%%%header_doc_include
+
+%%%impl_doc_include
+
+%% Note that mnesia considers all callbacks mandatory!!
+%%
+behaviour_info(callbacks) ->
+    [
+     {add_aliases, 1},         % (Aliases) -> ok
+     {check_definition, 4},    % (TypeAlias, Tab, Nodes, Properties) -> ok
+     {close_table, 2},         % (TypeAlias, Tab) -> ok
+     {create_table, 3},        % (TypeAlias, Tab, Properties) -> ok
+     {delete, 3},              % (TypeAlias, Tab, Key) -> true | ok
+     {delete_table, 2},        % (TypeAlias, Tab) -> ok
+     {first, 2},               % (TypeAlias, Tab) -> Key::Term | '$end_of_table'
+     {fixtable, 3},            % (TypeAlias, Tab, Bool) -> ok | true
+     {last, 2},                % (TypeAlias, Tab) -> Key::Term | '$end_of_table'
+     {index_is_consistent,3},  % (TypeAlias, IxTag, Bool) -> ok
+     {init_backend, 0},        % () -> ok
+     {info, 3},                % (TypeAlias, Tab, Item) -> Term
+     {insert, 3},              % (TypeAlias, Tab, Object) -> ok
+     {lookup, 3},              % (TypeAlias, Tab, Key) -> [Objects]
+     {is_index_consistent,2},  % (TypeAlias, IxTag) -> Bool
+     {load_table, 4},          % (TypeAlias, Tab, Reason, CsList) -> ok
+     {match_delete, 3},        % (TypeAlias, Tab, Pattern) -> ok
+     {next, 3},                % (TypeAlias, Tab, Key) -> Key::Term | '$end_of_table'
+     {prev, 3},                % (TypeAlias, Tab, Key) -> Key::Term | '$end_of_table'
+     {receiver_first_message, 4}, % (Sender, FirstMsg, Alias, Tab) -> {Size, State}
+     {receive_data, 5},        % (Data, Alias, Name, Sender, State) -> {more, State} | {{more, Msg}, State}
+     {receive_done, 4},        % (Alias, Tab, Sender, State) -> ok
+     {real_suffixes, 0},       % () -> [FileSuffix]
+     {remove_aliases, 1},      % (Aliases) -> ok
+     {repair_continuation, 2}, % (Continuation, MatchSpec) -> Continuation
+     {select, 1},              % (Continuation) -> {[Match], Continuation'} | '$end_of_table'
+     {select, 3},              % (TypeAlias, Tab, Pattern) -> {[Match], Continuation'} | '$end_of_table'
+     {select, 4},              % (TypeAlias, Tab, MatchSpec, Limit) {[Match], Continuation'} | '$end_of_table'
+     {sender_init, 4},         % (TypeAlias, Tab, LoadReason, Pid) ->
+					% {standard, Init(), Chunk()} | {Init(), Chunk()}
+     {semantics, 2},           % (TypeAlias, storage | types | index_fun | index_types) ->
+					% ram_copies | disc_copies, set | ordered_set | bag, fun(), ordered | bag
+     {slot, 3},                % (TypeAlias, Tab, Pos) -> '$end_of_table' | Objects | {error, Reason}
+     {sync_close_table, 2},    % (TypeAlias, Tab) -> ok
+     {tmp_suffixes, 0},        % () -> [FileSuffix]
+     {update_counter, 4},      % (TypeAlias, Tab, Counter, Val) -> NewVal
+     {validate_key, 6},        % (TypeAlias, Tab, RecName, Arity, Type, Key) -> {RecName, Arity, Type}
+     {validate_record, 6}      % (TypeAlias, Tab, RecName, Arity, Type, Obj) -> {RecName, Arity, Type}
+    ].
+
+%%%impl_doc_include
+
+%% -type tab() :: atom().
+%% -type alias() :: atom().
+%% -type rec_name() :: atom().
+%% -type type() :: set | bag | ordered_set.
+%% -type proplist() :: [{atom(), any()}].
+%% -type key() :: any().
+%% -type db_object() :: tuple().
+
+%% -type matchspec() :: ets:match_spec().
+%% -type limit() :: integer() | infinity.
+
+%% -type cont_fun() :: any().
+%% -type cont() :: '$end_of_table' | cont_fun().
+
+%% -callback check_definition(alias(), tab(), [node()], proplist()) -> ok.
+%% -callback create_table(alias(), tab(), proplist()) -> tab().
+%% -callback load_table(alias(), tab(), any()) -> ok.
+%% -callback delete_table(alias(), tab()) -> ok.
+%% -callback first(alias(), tab()) -> key().
+%% -callback last(alias(), tab()) -> key().
+%% -callback next(alias(), tab(), key()) -> key().
+%% -callback prev(alias(), tab(), key()) -> key().
+%% -callback insert(alias(), tab(), db_object()) -> ok.
+%% -callback lookup(alias(), tab(), key()) -> [db_object()].
+%% -callback delete(alias(), tab(), key()) -> ok.
+%% -callback update_counter(alias(), tab(), key(), integer()) -> integer().
+%% -callback select(cont()) -> {list(), cont()}.
+%% -callback select(alias(), tab(), matchspec()) -> list() | '$end_of_table'.
+%% -callback select(alias(), tab(), matchspec(), limit()) -> {list(), cont()}.
+%% -callback slot(alias(), tab(), integer()) -> key().
+%% -callback validate_key(alias(), tab(), rec_name(), arity(), type(), key()) ->
+%%     {rec_name(), arity(), type()}.
+%% -callback validate_record(alias(),tab(),rec_name(),arity(),type(),db_obj()) ->
+%%     {rec_name(), arity(), type()}.
+%% -callback repair_continuation(cont(), matchspec()) -> cont().
diff --git a/lib/mnesia/src/mnesia_backup.erl b/lib/mnesia/src/mnesia_backup.erl
index 736f2ed9bf..719e010c17 100644
--- a/lib/mnesia/src/mnesia_backup.erl
+++ b/lib/mnesia/src/mnesia_backup.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
-%%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_bup.erl b/lib/mnesia/src/mnesia_bup.erl
index fd87be1759..3e55deb958 100644
--- a/lib/mnesia/src/mnesia_bup.erl
+++ b/lib/mnesia/src/mnesia_bup.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -27,6 +28,7 @@
          fallback_exists/0,
          tm_fallback_start/1,
          create_schema/1,
+	 create_schema/2,
          install_fallback/1,
          install_fallback/2,
          uninstall_fallback/0,
@@ -45,7 +47,7 @@
          uninstall_fallback_master/2,
          local_uninstall_fallback/2,
          do_traverse_backup/7,
-         trav_apply/4
+         trav_apply/5
         ]).
 
 -include("mnesia.hrl").
@@ -78,45 +80,58 @@
 %% BunchOfRecords will be [] when the iteration is done.
 iterate(Mod, Fun, Opaque, Acc) ->
     R = #restore{bup_module = Mod, bup_data = Opaque},
-    case catch read_schema_section(R) of
-        {error, Reason} ->
-            {error, Reason};
-        {R2, {Header, Schema, Rest}} ->
-            case catch iter(R2, Header, Schema, Fun, Acc, Rest) of
-                {ok, R3, Res} ->
-                    catch safe_apply(R3, close_read, [R3#restore.bup_data]),
-                    {ok, Res};
-                {error, Reason} ->
-                    catch safe_apply(R2, close_read, [R2#restore.bup_data]),
-                    {error, Reason};
-                {'EXIT', Pid, Reason} ->
-                    catch safe_apply(R2, close_read, [R2#restore.bup_data]),
-                    {error, {'EXIT', Pid, Reason}};
-                {'EXIT', Reason} ->
-                    catch safe_apply(R2, close_read, [R2#restore.bup_data]),
-                    {error, {'EXIT', Reason}}
-            end
+    try read_schema_section(R) of
+	{R2, {Header, Schema, Rest}} ->
+            Ext = get_ext_types(Schema),
+	    try iter(R2, Header, Schema, Ext, Fun, Acc, Rest) of
+		{ok, R3, Res} ->
+		    close_read(R3),
+		    {ok, Res}
+	    catch throw:Err ->
+		    close_read(R2),
+		    Err;
+		  _:Reason ->
+		    close_read(R2),
+		    {error, {Reason, erlang:get_stacktrace()}}
+	    end
+    catch throw:{error,_} = Err ->
+	    Err
     end.
 
-iter(R, Header, Schema, Fun, Acc, []) ->
+get_ext_types(Schema) ->
+    try
+        List = lookup_schema(schema, Schema),
+        case lists:keyfind(user_properties, 1, List) of
+            {_, Props} ->
+                proplists:get_value(
+                  mnesia_backend_types, Props, []);
+            false ->
+                []
+        end
+    catch
+        throw:{error, {"Cannot lookup",_}} ->
+            []
+    end.
+
+iter(R, Header, Schema, Ext, Fun, Acc, []) ->
     case safe_apply(R, read, [R#restore.bup_data]) of
         {R2, []} ->
-            Res = Fun([], Header, Schema, Acc),
+            Res = Fun([], Header, Schema, Ext, Acc),
             {ok, R2, Res};
         {R2, BupItems} ->
-            iter(R2, Header, Schema, Fun, Acc, BupItems)
+            iter(R2, Header, Schema, Ext, Fun, Acc, BupItems)
     end;
-iter(R, Header, Schema, Fun, Acc, BupItems) ->
-    Acc2 = Fun(BupItems, Header, Schema, Acc),
-    iter(R, Header, Schema, Fun, Acc2, []).
+iter(R, Header, Schema, Ext, Fun, Acc, BupItems) ->
+    Acc2 = Fun(BupItems, Header, Schema, Ext, Acc),
+    iter(R, Header, Schema, Ext, Fun, Acc2, []).
 
 -spec safe_apply(#restore{}, atom(), list()) -> tuple().
 safe_apply(R, write, [_, Items]) when Items =:= [] ->
     R;
 safe_apply(R, What, Args) ->
-    Abort = fun(Re) -> abort_restore(R, What, Args, Re) end,
+    Abort = abort_restore_fun(R, What, Args),
     Mod = R#restore.bup_module,
-    case catch apply(Mod, What, Args) of
+    try apply(Mod, What, Args) of
 	{ok, Opaque, Items} when What =:= read ->
 	    {R#restore{bup_data = Opaque}, Items};
 	{ok, Opaque}  when What =/= read->
@@ -125,16 +140,23 @@ safe_apply(R, What, Args) ->
 	    Abort(Re);
 	Re ->
 	    Abort(Re)
+    catch _:Re ->
+	    Abort(Re)
     end.
 
-abort_restore(R, What, Args, Reason) ->
-    Mod = R#restore.bup_module,
-    Opaque = R#restore.bup_data,
+-spec abort_restore_fun(_, _, _) -> fun((_) -> no_return()).
+abort_restore_fun(R, What, Args) ->
+    fun(Re) -> abort_restore(R, What, Args, Re) end.
+
+abort_restore(R = #restore{bup_module=Mod}, What, Args, Reason) ->
     dbg_out("Restore aborted. ~p:~p~p -> ~p~n",
             [Mod, What, Args, Reason]),
-    catch apply(Mod, close_read, [Opaque]),
+    close_read(R),
     throw({error, Reason}).
 
+close_read(#restore{bup_module=Mod, bup_data=Opaque}) ->
+    ?SAFE(Mod:close_read(Opaque)).
+
 fallback_to_schema() ->
     Fname = fallback_bup(),
     fallback_to_schema(Fname).
@@ -145,45 +167,41 @@ fallback_to_schema(Fname) ->
         {error, Reason} ->
             {error, Reason};
         Schema ->
-            case catch lookup_schema(schema, Schema) of
-                {error, _} ->
-                    {error, "No schema in fallback"};
-                List ->
-                    {ok, fallback, List}
+            try lookup_schema(schema, Schema) of
+		List -> {ok, fallback, List}
+	    catch throw:_ ->
+		    {error, "No schema in fallback"}
             end
     end.
 
 %% Opens Opaque reads schema and then close
 read_schema(Mod, Opaque) ->
     R = #restore{bup_module = Mod, bup_data = Opaque},
-    case catch read_schema_section(R) of
-        {error, Reason} ->
-            {error, Reason};
+    try read_schema_section(R) of
         {R2, {_Header, Schema, _}} ->
-            catch safe_apply(R2, close_read, [R2#restore.bup_data]),
-            Schema
+	    close_read(R2),
+	    Schema
+    catch throw:{error,_} = Error ->
+	    Error
     end.
 
 %% Open backup media and extract schema
 %% rewind backup media and leave it open
 %% Returns {R, {Header, Schema}}
 read_schema_section(R) ->
-    case catch do_read_schema_section(R) of
-        {'EXIT', Reason} ->
-            catch safe_apply(R, close_read, [R#restore.bup_data]),
-            {error, {'EXIT', Reason}};
-        {error, Reason} ->
-            catch safe_apply(R, close_read, [R#restore.bup_data]),
-            {error, Reason};
-        {R2, {H, Schema, Rest}} ->
-            Schema2 = convert_schema(H#log_header.log_version, Schema),
-            {R2, {H, Schema2, Rest}}
-    end.
+    {R2, {H, Schema, Rest}} = do_read_schema_section(R),
+    Schema2 = convert_schema(H#log_header.log_version, Schema),
+    {R2, {H, Schema2, Rest}}.
 
 do_read_schema_section(R) ->
     R2 = safe_apply(R, open_read, [R#restore.bup_data]),
-    {R3, RawSchema} = safe_apply(R2, read, [R2#restore.bup_data]),
-    do_read_schema_section(R3, verify_header(RawSchema), []).
+    try
+	{R3, RawSchema} = safe_apply(R2, read, [R2#restore.bup_data]),
+	do_read_schema_section(R3, verify_header(RawSchema), [])
+    catch T:E ->
+	    close_read(R2),
+	    erlang:raise(T,E,erlang:get_stacktrace())
+    end.
 
 do_read_schema_section(R, {ok, B, C, []}, Acc) ->
     case safe_apply(R, read, [R#restore.bup_data]) of
@@ -201,7 +219,7 @@ do_read_schema_section(R, {ok, B, _C, Rest}, Acc) ->
     {R, {B, Acc, Rest}};
 
 do_read_schema_section(_R, {error, Reason}, _Acc) ->
-    {error, Reason}.
+    throw({error, Reason}).
 
 verify_header([H | RawSchema]) when is_record(H, log_header) ->
     Current = mnesia_log:backup_log_header(),
@@ -218,7 +236,7 @@ verify_header([H | RawSchema]) when is_record(H, log_header) ->
             {error, {"Bad kind of header. Cannot be used as backup.", H}}
     end;
 verify_header(RawSchema) ->
-    {error, {"Missing header. Cannot be used as backup.", catch hd(RawSchema)}}.
+    {error, {"Missing header. Cannot be used as backup.", ?CATCH(hd(RawSchema))}}.
 
 refresh_cookie(Schema, NewCookie) ->
     case lists:keysearch(schema, 2, Schema) of
@@ -261,7 +279,7 @@ convert_0_1(Schema) ->
             Cs = mnesia_schema:list2cs(List),
             convert_0_1(Schema2, [], Cs);
         false ->
-            List = mnesia_schema:get_initial_schema(disc_copies, [node()]),
+            List = mnesia_schema:get_initial_schema(disc_copies, [node()], []),
             Cs = mnesia_schema:list2cs(List),
             convert_0_1(Schema, [], Cs)
     end.
@@ -309,16 +327,19 @@ schema2bup({schema, Tab, TableDef}) ->
 %% Create schema on the given nodes
 %% Requires that old schemas has been deleted
 %% Returns ok | {error, Reason}
-create_schema([]) ->
-    create_schema([node()]);
-create_schema(Ns) when is_list(Ns) ->
+create_schema(Nodes) ->
+    create_schema(Nodes, []).
+
+create_schema([], Props) ->
+    create_schema([node()], Props);
+create_schema(Ns, Props) when is_list(Ns), is_list(Props) ->
     case is_set(Ns) of
         true ->
-            create_schema(Ns, mnesia_schema:ensure_no_schema(Ns));
+            create_schema(Ns, mnesia_schema:ensure_no_schema(Ns), Props);
         false ->
             {error, {combine_error, Ns}}
     end;
-create_schema(Ns) ->
+create_schema(Ns, _Props) ->
     {error, {badarg, Ns}}.
 
 is_set(List) when is_list(List) ->
@@ -326,7 +347,7 @@ is_set(List) when is_list(List) ->
 is_set(_) ->
     false.
 
-create_schema(Ns, ok) ->
+create_schema(Ns, ok, Props) ->
     %% Ensure that we access the intended Mnesia
     %% directory. This function may not be called
     %% during startup since it will cause the
@@ -345,7 +366,7 @@ create_schema(Ns, ok) ->
                             Str = mk_str(),
                             File = mnesia_lib:dir(Str),
                             file:delete(File),
-                            case catch make_initial_backup(Ns, File, Mod) of
+                            try make_initial_backup(Ns, File, Mod, Props) of
                                 {ok, _Res} ->
                                     case do_install_fallback(File, Mod) of
                                         ok ->
@@ -353,8 +374,8 @@ create_schema(Ns, ok) ->
                                             ok;
                                         {error, Reason} ->
                                             {error, Reason}
-                                    end;
-                                {error, Reason} ->
+                                    end
+			    catch throw:{error, Reason} ->
                                     {error, Reason}
                             end
                     end
@@ -362,17 +383,20 @@ create_schema(Ns, ok) ->
         {error, Reason} ->
             {error, Reason}
     end;
-create_schema(_Ns, {error, Reason}) ->
+create_schema(_Ns, {error, Reason}, _) ->
     {error, Reason};
-create_schema(_Ns, Reason) ->
+create_schema(_Ns, Reason, _) ->
     {error, Reason}.
 
 mk_str() ->
-    Now = [integer_to_list(I) || I <- tuple_to_list(now())],
+    Now = integer_to_list(erlang:unique_integer([positive])),
     lists:concat([node()] ++ Now ++ ".TMP").
 
 make_initial_backup(Ns, Opaque, Mod) ->
-    Orig = mnesia_schema:get_initial_schema(disc_copies, Ns),
+    make_initial_backup(Ns, Opaque, Mod, []).
+
+make_initial_backup(Ns, Opaque, Mod, Props) ->
+    Orig = mnesia_schema:get_initial_schema(disc_copies, Ns, Props),
     Modded = proplists:delete(storage_properties, proplists:delete(majority, Orig)),
     Schema = [{schema, schema, Modded}],
     O2 = do_apply(Mod, open_write, [Opaque], Opaque),
@@ -384,10 +408,11 @@ make_initial_backup(Ns, Opaque, Mod) ->
 do_apply(_, write, [_, Items], Opaque) when Items =:= [] ->
     Opaque;
 do_apply(Mod, What, Args, _Opaque) ->
-    case catch apply(Mod, What, Args) of
+    try apply(Mod, What, Args) of
         {ok, Opaque2} ->  Opaque2;
-        {error, Reason} -> throw({error, Reason});
-        {'EXIT', Reason} -> throw({error, {'EXIT', Reason}})
+        {error, Reason} -> throw({error, Reason})
+    catch _:Reason ->
+	    throw({error, {'EXIT', Reason}})
     end.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -425,11 +450,11 @@ do_install_fallback(_Opaque, Args) ->
     {error, {badarg, Args}}.
 
 check_fallback_args([Arg | Tail], FA) ->
-    case catch check_fallback_arg_type(Arg, FA) of
-        {'EXIT', _Reason} ->
-            {error, {badarg, Arg}};
+    try check_fallback_arg_type(Arg, FA) of
         FA2 ->
             check_fallback_args(Tail, FA2)
+    catch error:_ ->
+	    {error, {badarg, Arg}}
     end;
 check_fallback_args([], FA) ->
     {ok, FA}.
@@ -484,38 +509,38 @@ install_fallback_master(ClientPid, FA) ->
     State = {start, FA},
     Opaque = FA#fallback_args.opaque,
     Mod = FA#fallback_args.module,
-    Res = (catch iterate(Mod, fun restore_recs/4, Opaque, State)),
+    Res = iterate(Mod, fun restore_recs/5, Opaque, State),
     unlink(ClientPid),
     ClientPid ! {self(), Res},
     exit(shutdown).
 
-restore_recs(_, _, _, stop) ->
+restore_recs(_, _, _, _, stop) ->
     throw({error, "restore_recs already stopped"});
 
-restore_recs(Recs, Header, Schema, {start, FA}) ->
+restore_recs(Recs, Header, Schema, Ext, {start, FA}) ->
     %% No records in backup
     Schema2 = convert_schema(Header#log_header.log_version, Schema),
     CreateList = lookup_schema(schema, Schema2),
-    case catch mnesia_schema:list2cs(CreateList) of
-        {'EXIT', Reason} ->
-            throw({error, {"Bad schema in restore_recs", Reason}});
+    try mnesia_schema:list2cs(CreateList) of
         Cs ->
             Ns = get_fallback_nodes(FA, Cs#cstruct.disc_copies),
             global:set_lock({{mnesia_table_lock, schema}, self()}, Ns, infinity),
             Args = [self(), FA],
             Pids = [spawn_link(N, ?MODULE, fallback_receiver, Args) || N <- Ns],
             send_fallback(Pids, {start, Header, Schema2}),
-            Res = restore_recs(Recs, Header, Schema2, Pids),
+            Res = restore_recs(Recs, Header, Schema2, Ext, Pids),
             global:del_lock({{mnesia_table_lock, schema}, self()}, Ns),
             Res
+    catch _:Reason ->
+            throw({error, {"Bad schema in restore_recs", Reason}})
     end;
 
-restore_recs([], _Header, _Schema, Pids) ->
+restore_recs([], _Header, _Schema, _Ext, Pids) ->
     send_fallback(Pids, swap),
     send_fallback(Pids, stop),
     stop;
 
-restore_recs(Recs, _, _, Pids) ->
+restore_recs(Recs, _, _, _, Pids) ->
     send_fallback(Pids, {records, Recs}),
     Pids.
 
@@ -579,45 +604,46 @@ fallback_tmp_name() -> "FALLBACK.TMP".
 fallback_receiver(Master, FA) ->
     process_flag(trap_exit, true),
 
-    case catch register(mnesia_fallback, self()) of
-        {'EXIT', _} ->
-            Reason = {already_exists, node()},
-            local_fallback_error(Master, Reason);
-        true ->
-            FA2 = check_fallback_dir(Master, FA),
-            Bup = FA2#fallback_args.fallback_bup,
-            case mnesia_lib:exists(Bup) of
-                true ->
-                    Reason2 = {already_exists, node()},
-                    local_fallback_error(Master, Reason2);
-                false ->
-                    Mod = mnesia_backup,
-                    Tmp = FA2#fallback_args.fallback_tmp,
-                    R = #restore{mode = replace,
-                                 bup_module = Mod,
-                                 bup_data = Tmp},
-                    file:delete(Tmp),
-                    case catch fallback_receiver_loop(Master, R, FA2, schema) of
-                        {error, Reason} ->
-                            local_fallback_error(Master, Reason);
-                        Other ->
-                            exit(Other)
-                    end
-            end
-    end.
+    Res = try
+	      register(mnesia_fallback, self()),
+	      FA2 = check_fallback_dir(FA),
+	      Bup = FA2#fallback_args.fallback_bup,
+	      false = mnesia_lib:exists(Bup),
+	      Mod = mnesia_backup,
+	      Tmp = FA2#fallback_args.fallback_tmp,
+	      R = #restore{mode = replace,
+			   bup_module = Mod,
+			   bup_data = Tmp},
+	      file:delete(Tmp),
+	      fallback_receiver_loop(Master, R, FA2, schema)
+	  catch
+	      error:_ ->
+		  Reason = {already_exists, node()},
+		  local_fallback_error(Master, Reason);
+	      throw:{error, Reason} ->
+		  local_fallback_error(Master, Reason)
+	  end,
+    exit(Res).
 
 local_fallback_error(Master, Reason) ->
     Master ! {self(), {error, Reason}},
     unlink(Master),
     exit(Reason).
 
+
 check_fallback_dir(Master, FA) ->
+    try check_fallback_dir(FA)
+    catch throw:{error,Reason} ->
+	    local_fallback_error(Master, Reason)
+    end.
+
+check_fallback_dir(FA) ->
     case mnesia:system_info(schema_location) of
         ram ->
             Reason = {has_no_disc, node()},
-            local_fallback_error(Master, Reason);
+            throw({error, Reason});
         _ ->
-            Dir = check_fallback_dir_arg(Master, FA),
+            Dir = check_fallback_dir_arg(FA),
             Bup = filename:join([Dir, fallback_name()]),
             Tmp = filename:join([Dir, fallback_tmp_name()]),
             FA#fallback_args{fallback_bup = Bup,
@@ -625,22 +651,20 @@ check_fallback_dir(Master, FA) ->
                              mnesia_dir = Dir}
     end.
 
-check_fallback_dir_arg(Master, FA) ->
+check_fallback_dir_arg(FA) ->
     case FA#fallback_args.use_default_dir of
         true ->
             mnesia_lib:dir();
         false when FA#fallback_args.scope =:= local ->
             Dir = FA#fallback_args.mnesia_dir,
-            case catch mnesia_monitor:do_check_type(dir, Dir) of
-                {'EXIT', _R} ->
+            try mnesia_monitor:do_check_type(dir, Dir)
+	    catch _:_ ->
                     Reason = {badarg, {dir, Dir}, node()},
-                    local_fallback_error(Master, Reason);
-                AbsDir->
-                    AbsDir
-            end;
+		    throw({error, Reason})
+	    end;
         false when FA#fallback_args.scope =:= global ->
             Reason = {combine_error, global, dir, node()},
-            local_fallback_error(Master, Reason)
+            throw({error, Reason})
     end.
 
 fallback_receiver_loop(Master, R, FA, State) ->
@@ -666,7 +690,7 @@ fallback_receiver_loop(Master, R, FA, State) ->
             Bup = FA#fallback_args.fallback_bup,
             Tmp = FA#fallback_args.fallback_tmp,
             throw_bad_res(ok, file:rename(Tmp, Bup)),
-            catch mnesia_lib:set(active_fallback, true),
+            ?SAFE(mnesia_lib:set(active_fallback, true)),
             ?eval_debug_fun({?MODULE, fallback_receiver_loop, post_swap}, []),
             Master ! {self(), ok},
             fallback_receiver_loop(Master, R, FA, stop);
@@ -697,7 +721,7 @@ throw_bad_res(_Expected, Actual) -> throw({error, Actual}).
 tm_fallback_start(IgnoreFallback) ->
     mnesia_schema:lock_schema(),
     Res = do_fallback_start(fallback_exists(), IgnoreFallback),
-    mnesia_schema: unlock_schema(),
+    mnesia_schema:unlock_schema(),
     case Res of
         ok -> ok;
         {error, Reason} -> exit(Reason)
@@ -715,9 +739,9 @@ do_fallback_start(true, false) ->
     BupFile = fallback_bup(),
     Mod = mnesia_backup,
     LocalTabs = ?ets_new_table(mnesia_local_tables, [set, public, {keypos, 2}]),
-    case catch iterate(Mod, fun restore_tables/4, BupFile, {start, LocalTabs}) of
+    case iterate(Mod, fun restore_tables/5, BupFile, {start, LocalTabs}) of
         {ok, _Res} ->
-            catch dets:close(schema),
+            ?SAFE(dets:close(schema)),
             TmpSchema = mnesia_lib:tab2tmp(schema),
             DatSchema = mnesia_lib:tab2dat(schema),
 	    AllLT  = ?ets_match_object(LocalTabs, '_'),
@@ -733,28 +757,27 @@ do_fallback_start(true, false) ->
                     {error, {"Cannot start from fallback. Rename error.", Reason}}
             end;
         {error, Reason} ->
-            {error, {"Cannot start from fallback", Reason}};
-        {'EXIT', Reason} ->
             {error, {"Cannot start from fallback", Reason}}
     end.
 
-restore_tables(All=[Rec | Recs], Header, Schema, State={local, LocalTabs, LT}) ->
+restore_tables(All=[Rec | Recs], Header, Schema, Ext,
+               State={local, LocalTabs, LT}) ->
     Tab = element(1, Rec),
     if
         Tab =:= LT#local_tab.name ->
             Key = element(2, Rec),
             (LT#local_tab.add)(Tab, Key, Rec, LT),
-            restore_tables(Recs, Header, Schema, State);
+            restore_tables(Recs, Header, Schema, Ext, State);
         true ->
             NewState = {new, LocalTabs},
-            restore_tables(All, Header, Schema, NewState)
+            restore_tables(All, Header, Schema, Ext, NewState)
     end;
-restore_tables(All=[Rec | Recs], Header, Schema, {new, LocalTabs}) ->
+restore_tables(All=[Rec | Recs], Header, Schema, Ext, {new, LocalTabs}) ->
     Tab = element(1, Rec),
     case ?ets_lookup(LocalTabs, Tab) of
         [] ->
             State = {not_local, LocalTabs, Tab},
-            restore_tables(Recs, Header, Schema, State);
+            restore_tables(Recs, Header, Schema, Ext, State);
         [LT] when is_record(LT, local_tab) ->
 	    State = {local, LocalTabs, LT},
 	    case LT#local_tab.opened of
@@ -763,38 +786,39 @@ restore_tables(All=[Rec | Recs], Header, Schema, {new, LocalTabs}) ->
 		    (LT#local_tab.open)(Tab, LT),
 		    ?ets_insert(LocalTabs,LT#local_tab{opened=true})
 	    end,
-            restore_tables(All, Header, Schema, State)
+            restore_tables(All, Header, Schema, Ext, State)
     end;
-restore_tables(All=[Rec | Recs], Header, Schema, S = {not_local, LocalTabs, PrevTab}) ->
+restore_tables(All=[Rec | Recs], Header, Schema, Ext,
+               S = {not_local, LocalTabs, PrevTab}) ->
     Tab = element(1, Rec),
     if
         Tab =:= PrevTab ->
-            restore_tables(Recs, Header, Schema, S);
+            restore_tables(Recs, Header, Schema, Ext, S);
         true ->
             State = {new, LocalTabs},
-            restore_tables(All, Header, Schema, State)
+            restore_tables(All, Header, Schema, Ext, State)
     end;
-restore_tables(Recs, Header, Schema, {start, LocalTabs}) ->
+restore_tables(Recs, Header, Schema, Ext, {start, LocalTabs}) ->
     Dir = mnesia_lib:dir(),
     OldDir = filename:join([Dir, "OLD_DIR"]),
     mnesia_schema:purge_dir(OldDir, []),
     mnesia_schema:purge_dir(Dir, [fallback_name()]),
-    init_dat_files(Schema, LocalTabs),
+    init_dat_files(Schema, Ext, LocalTabs),
     State = {new, LocalTabs},
-    restore_tables(Recs, Header, Schema, State);
-restore_tables([], _Header, _Schema, State) ->
+    restore_tables(Recs, Header, Schema, Ext, State);
+restore_tables([], _Header, _Schema, _Ext, State) ->
     State.
 
 %% Creates all neccessary dat files and inserts
 %% the table definitions in the schema table
 %%
 %% Returns a list of local_tab tuples for all local tables
-init_dat_files(Schema, LocalTabs) ->
+init_dat_files(Schema, Ext, LocalTabs) ->
     TmpFile = mnesia_lib:tab2tmp(schema),
     Args = [{file, TmpFile}, {keypos, 2}, {type, set}],
     case dets:open_file(schema, Args) of % Assume schema lock
         {ok, _} ->
-            create_dat_files(Schema, LocalTabs),
+            create_dat_files(Schema, Ext, LocalTabs),
             ok = dets:close(schema),
             LocalTab = #local_tab{name         = schema,
                                   storage_type = disc_copies,
@@ -809,10 +833,10 @@ init_dat_files(Schema, LocalTabs) ->
             throw({error, {"Cannot open file", schema, Args, Reason}})
     end.
 
-create_dat_files([{schema, schema, TabDef} | Tail], LocalTabs) ->
+create_dat_files([{schema, schema, TabDef} | Tail], Ext, LocalTabs) ->
     ok = dets:insert(schema, {schema, schema, TabDef}),
-    create_dat_files(Tail, LocalTabs);
-create_dat_files([{schema, Tab, TabDef} | Tail], LocalTabs) ->
+    create_dat_files(Tail, Ext, LocalTabs);
+create_dat_files([{schema, Tab, TabDef} | Tail], Ext, LocalTabs) ->
     TmpFile = mnesia_lib:tab2tmp(Tab),
     DatFile = mnesia_lib:tab2dat(Tab),
     DclFile = mnesia_lib:tab2dcl(Tab),
@@ -825,56 +849,21 @@ create_dat_files([{schema, Tab, TabDef} | Tail], LocalTabs) ->
 
     mnesia_lib:dets_sync_close(Tab),
     file:delete(TmpFile),
-    Cs = mnesia_schema:list2cs(TabDef),
+    Cs = mnesia_schema:list2cs(TabDef, Ext),
     ok = dets:insert(schema, {schema, Tab, TabDef}),
     RecName = Cs#cstruct.record_name,
     Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
+    delete_ext(Storage, Tab),
+    Semantics = mnesia_lib:semantics(Storage, storage),
     if
-	Storage =:= unknown ->
+	Semantics =:= undefined ->
             ok = dets:delete(schema, {schema, Tab}),
-            create_dat_files(Tail, LocalTabs);
-        Storage =:= disc_only_copies ->
-            Args = [{file, TmpFile}, {keypos, 2},
-                    {type, mnesia_lib:disk_type(Tab, Cs#cstruct.type)}],
-            Open = fun(T, LT) when T =:= LT#local_tab.name ->
-                           case mnesia_lib:dets_sync_open(T, Args) of
-                               {ok, _} ->
-                                   ok;
-                               {error, Reason} ->
-                                   throw({error, {"Cannot open file", T, Args, Reason}})
-                           end
-                   end,
-            Add = fun(T, Key, Rec, LT) when T =:= LT#local_tab.name ->
-                          case Rec of
-                              {_T, Key} ->
-                                  ok = dets:delete(T, Key);
-                              (Rec) when T =:= RecName ->
-                                  ok = dets:insert(Tab, Rec);
-                              (Rec) ->
-                                  Rec2 = setelement(1, Rec, RecName),
-                                  ok = dets:insert(T, Rec2)
-                          end
-                  end,
-            Close = fun(T, LT) when T =:= LT#local_tab.name ->
-                            mnesia_lib:dets_sync_close(T)
-                    end,
-	    Swap = fun(T, LT) when T =:= LT#local_tab.name ->
-			   Expunge(),
-			   case LT#local_tab.opened of
-			       true ->
-				   Close(T,LT);
-			       false ->
-				   Open(T,LT),
-				   Close(T,LT)
-			   end,
-			   case file:rename(TmpFile, DatFile) of
-			       ok ->
-				   ok;
-			       {error, Reason} ->
-				   mnesia_lib:fatal("Cannot rename file ~p -> ~p: ~p~n",
-						    [TmpFile, DatFile, Reason])
-			   end
-		   end,
+            create_dat_files(Tail, Ext, LocalTabs);
+        Semantics =:= disc_only_copies ->
+	    Open = disc_only_open_fun(Storage, Cs),
+	    Add = disc_only_add_fun(Storage, Cs),
+	    Close = disc_only_close_fun(Storage),
+	    Swap = disc_only_swap_fun(Storage, Expunge, Open, Close),
             LocalTab = #local_tab{name         = Tab,
                                   storage_type = Storage,
                                   open         = Open,
@@ -884,8 +873,8 @@ create_dat_files([{schema, Tab, TabDef} | Tail], LocalTabs) ->
                                   record_name  = RecName,
                                   opened       = false},
             ?ets_insert(LocalTabs, LocalTab),
-	    create_dat_files(Tail, LocalTabs);
-        Storage =:= ram_copies; Storage =:= disc_copies ->
+	    create_dat_files(Tail, Ext, LocalTabs);
+        Semantics =:= ram_copies; Storage =:= disc_copies ->
 	    Open = fun(T, LT) when T =:= LT#local_tab.name ->
 			   mnesia_log:open_log({?MODULE, T},
 					       mnesia_log:dcl_log_header(),
@@ -946,18 +935,97 @@ create_dat_files([{schema, Tab, TabDef} | Tail], LocalTabs) ->
 				  opened       = false
 				 },
             ?ets_insert(LocalTabs, LocalTab),
-            create_dat_files(Tail, LocalTabs)
+            create_dat_files(Tail, Ext, LocalTabs);
+	true ->
+	    error({unknown_semantics, [{semantics, Semantics},
+				       {tabdef, TabDef},
+				       {ext, Ext}]})
     end;
-create_dat_files([{schema, Tab} | Tail], LocalTabs) ->
+create_dat_files([{schema, Tab} | Tail], Ext, LocalTabs) ->
     ?ets_delete(LocalTabs, Tab),
     ok = dets:delete(schema, {schema, Tab}),
     TmpFile = mnesia_lib:tab2tmp(Tab),
     mnesia_lib:dets_sync_close(Tab),
     file:delete(TmpFile),
-    create_dat_files(Tail, LocalTabs);
-create_dat_files([], _LocalTabs) ->
+    create_dat_files(Tail, Ext, LocalTabs);
+create_dat_files([], _Ext, _LocalTabs) ->
     ok.
 
+delete_ext({ext, Alias, Mod}, Tab) ->
+    Mod:close_table(Alias, Tab),
+    Mod:delete_table(Alias, Tab),
+    ok;
+delete_ext(_, _) ->
+    ok.
+
+
+disc_only_open_fun(disc_only_copies, #cstruct{name = Tab} =Cs) ->
+    TmpFile = mnesia_lib:tab2tmp(Tab),
+    Args = [{file, TmpFile}, {keypos, 2},
+	    {type, mnesia_lib:disk_type(Tab, Cs#cstruct.type)}],
+    fun(T, LT) when T =:= LT#local_tab.name ->
+	    case mnesia_lib:dets_sync_open(T, Args) of
+		{ok, _} ->
+		    ok;
+		{error, Reason} ->
+		    throw({error, {"Cannot open file", T, Args, Reason}})
+	    end
+    end;
+disc_only_open_fun({ext,Alias,Mod}, Cs) ->
+    fun(T, LT) when T =:= LT#local_tab.name ->
+	    ok = Mod:load_table(Alias, T, restore, mnesia_schema:cs2list(Cs))
+    end.
+
+disc_only_add_fun(Storage, #cstruct{name = Tab,
+				    record_name = RecName}) ->
+    fun(T, Key, Rec, #local_tab{name = T}) when T =:= Tab->
+	    case Rec of
+		{_T, Key} ->
+		    ok = mnesia_lib:db_erase(Storage, T, Key);
+		(Rec) when T =:= RecName ->
+		    ok = mnesia_lib:db_put(Storage, T, Rec);
+		(Rec) ->
+		    ok = mnesia_lib:db_put(Storage, T,
+					   setelement(1, Rec, RecName))
+	    end
+    end.
+
+disc_only_close_fun(disc_only_copies) ->
+    fun(T, LT) when T =:= LT#local_tab.name ->
+	    mnesia_lib:dets_sync_close(T)
+    end;
+disc_only_close_fun({ext, Alias, Mod}) ->
+    fun(T, _LT) ->
+	    Mod:sync_close_table(Alias, T)
+    end.
+
+
+disc_only_swap_fun(disc_only_copies, Expunge, Open, Close) ->
+    fun(T, LT) when T =:= LT#local_tab.name ->
+            TmpFile = mnesia_lib:tab2tmp(T),
+            DatFile = mnesia_lib:tab2dat(T),
+	    Expunge(),
+	    case LT#local_tab.opened of
+		true ->
+		    Close(T,LT);
+		false ->
+		    Open(T,LT),
+		    Close(T,LT)
+	    end,
+	    case file:rename(TmpFile, DatFile) of
+		ok ->
+		    ok;
+		{error, Reason} ->
+		    mnesia_lib:fatal("Cannot rename file ~p -> ~p: ~p~n",
+				     [TmpFile, DatFile, Reason])
+	    end
+    end;
+disc_only_swap_fun({ext, _Alias, _Mod}, _Expunge, _Open, Close) ->
+    fun(T, #local_tab{name = T} = LT) ->
+	    Close(T, LT)
+    end.
+
+
 uninstall_fallback() ->
     uninstall_fallback([{scope, global}]).
 
@@ -996,10 +1064,10 @@ uninstall_fallback_master(ClientPid, FA) ->
     case fallback_to_schema(Bup) of
         {ok, fallback, List} ->
             Cs = mnesia_schema:list2cs(List),
-            case catch get_fallback_nodes(FA, Cs#cstruct.disc_copies) of
+            try get_fallback_nodes(FA, Cs#cstruct.disc_copies) of
                 Ns when is_list(Ns) ->
-                    do_uninstall(ClientPid, Ns, FA);
-                {error, Reason} ->
+                    do_uninstall(ClientPid, Ns, FA)
+	    catch throw:{error, Reason} ->
                     local_fallback_error(ClientPid, Reason)
             end;
         {error, Reason} ->
@@ -1042,21 +1110,17 @@ local_uninstall_fallback(Master, FA) ->
     %% Don't trap exit
 
     register(mnesia_fallback, self()),        % May exit
-    FA2 = check_fallback_dir(Master, FA), % May exit
+    FA2 = check_fallback_dir(Master, FA),  % May exit
     Master ! {self(), started},
 
     receive
         {Master, do_uninstall} ->
             ?eval_debug_fun({?MODULE, uninstall_fallback2, pre_delete}, []),
-            catch mnesia_lib:set(active_fallback, false),
+            ?SAFE(mnesia_lib:set(active_fallback, false)),
             Tmp = FA2#fallback_args.fallback_tmp,
             Bup = FA2#fallback_args.fallback_bup,
             file:delete(Tmp),
-            Res =
-                case fallback_exists(Bup) of
-                    true -> file:delete(Bup);
-                    false -> ok
-                end,
+            Res = file:delete(Bup),
             ?eval_debug_fun({?MODULE, uninstall_fallback2, post_delete}, []),
             Master ! {self(), Res},
             unlink(Master),
@@ -1075,10 +1139,8 @@ rec_uninstall(ClientPid, [Pid | Pids], AccRes) ->
         {Pid, BadRes} ->
             rec_uninstall(ClientPid, Pids, BadRes)
     end;
-rec_uninstall(ClientPid, [], Res) ->
-    ClientPid ! {self(), Res},
-    unlink(ClientPid),
-    exit(normal).
+rec_uninstall(_, [], Res) ->
+    Res.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Backup traversal
@@ -1129,30 +1191,29 @@ do_traverse_backup(ClientPid, Source, SourceMod, Target, TargetMod, Fun, Acc) ->
     Iter =
         if
             TargetMod =/= read_only ->
-                case catch do_apply(TargetMod, open_write, [Target], Target) of
-                    {error, Error} ->
+                try do_apply(TargetMod, open_write, [Target], Target)
+		catch throw:{error, Error} ->
                         unlink(ClientPid),
                         ClientPid ! {iter_done, self(), {error, Error}},
-                        exit(Error);
-                    Else -> Else
+                        exit(Error)
                 end;
             true ->
                 ignore
         end,
     A = {start, Fun, Acc, TargetMod, Iter},
     Res =
-        case iterate(SourceMod, fun trav_apply/4, Source, A) of
+        case iterate(SourceMod, fun trav_apply/5, Source, A) of
             {ok, {iter, _, Acc2, _, Iter2}} when TargetMod =/= read_only ->
-                case catch do_apply(TargetMod, commit_write, [Iter2], Iter2) of
-                    {error, Reason} ->
-                        {error, Reason};
-                    _ ->
-                        {ok, Acc2}
+                try
+		    do_apply(TargetMod, commit_write, [Iter2], Iter2),
+		    {ok, Acc2}
+		catch throw:{error, Reason} ->
+                        {error, Reason}
                 end;
             {ok, {iter, _, Acc2, _, _}} ->
                 {ok, Acc2};
             {error, Reason} when TargetMod =/= read_only->
-                catch do_apply(TargetMod, abort_write, [Iter], Iter),
+                ?CATCH(do_apply(TargetMod, abort_write, [Iter], Iter)),
                 {error, {"Backup traversal failed", Reason}};
             {error, Reason} ->
                 {error, {"Backup traversal failed", Reason}}
@@ -1160,7 +1221,7 @@ do_traverse_backup(ClientPid, Source, SourceMod, Target, TargetMod, Fun, Acc) ->
     unlink(ClientPid),
     ClientPid ! {iter_done, self(), Res}.
 
-trav_apply(Recs, _Header, _Schema, {iter, Fun, Acc, Mod, Iter}) ->
+trav_apply(Recs, _Header, _Schema, _Ext, {iter, Fun, Acc, Mod, Iter}) ->
     {NewRecs, Acc2} = filter_foldl(Fun, Acc, Recs),
     if
         Mod =/= read_only, NewRecs =/= [] ->
@@ -1169,7 +1230,7 @@ trav_apply(Recs, _Header, _Schema, {iter, Fun, Acc, Mod, Iter}) ->
         true ->
             {iter, Fun, Acc2, Mod, Iter}
     end;
-trav_apply(Recs, Header, Schema, {start, Fun, Acc, Mod, Iter}) ->
+trav_apply(Recs, Header, Schema, Ext, {start, Fun, Acc, Mod, Iter}) ->
     Iter2 =
         if
             Mod =/= read_only ->
@@ -1177,8 +1238,9 @@ trav_apply(Recs, Header, Schema, {start, Fun, Acc, Mod, Iter}) ->
             true ->
                 Iter
         end,
-    TravAcc = trav_apply(Schema, Header, Schema, {iter, Fun, Acc, Mod, Iter2}),
-    trav_apply(Recs, Header, Schema, TravAcc).
+    TravAcc = trav_apply(Schema, Header, Schema, Ext,
+                         {iter, Fun, Acc, Mod, Iter2}),
+    trav_apply(Recs, Header, Schema, Ext, TravAcc).
 
 filter_foldl(Fun, Acc, [Head|Tail]) ->
     case Fun(Head, Acc) of
diff --git a/lib/mnesia/src/mnesia_checkpoint.erl b/lib/mnesia/src/mnesia_checkpoint.erl
index eb8fe38908..9eb939e8d3 100644
--- a/lib/mnesia/src/mnesia_checkpoint.erl
+++ b/lib/mnesia/src/mnesia_checkpoint.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -31,8 +32,7 @@
 	 tm_retain/5,
 	 tm_enter_pending/1,
 	 tm_enter_pending/3,
-	 tm_exit_pending/1,
-	 convert_cp_record/1
+	 tm_exit_pending/1
 	]).
 
 %% Public interface
@@ -69,12 +69,12 @@
 -import(mnesia_lib, [add/2, del/2, set/2, unset/1]).
 -import(mnesia_lib, [dbg_out/2]).
 
--record(checkpoint_args, {name = {now(), node()},
+-record(checkpoint_args, {name = {erlang:unique_integer([positive]), node()},
 			  allow_remote = true,
 			  ram_overrides_dump = false,
 			  nodes = [],
 			  node = node(),
-			  now = now(),
+			  now,  %% unused
 			  cookie = ?unique_cookie,
 			  min = [],
 			  max = [],
@@ -88,25 +88,6 @@
 			  pid
 			 }).
 
-%% Old record definition
--record(checkpoint, {name,
-		     allow_remote,
-		     ram_overrides_dump,
-		     nodes,
-		     node,
-		     now,
-		     min,
-		     max,
-		     pending_tab,
-		     wait_for_old,
-		     is_activated,
-		     ignore_new,
-		     retainers,
-		     iterators,
-		     supervisor,
-		     pid
-		    }).
-
 -record(retainer, {cp_name, tab_name, store, writers = [], really_retain = true}).
 
 -record(iter, {tab_name, oid_tab, main_tab, retainer_tab, source, val, pid}).
@@ -129,15 +110,6 @@ tm_prepare(Cp) when is_record(Cp, checkpoint_args) ->
 	    start_retainer(Cp);
 	true ->
 	    {error, {already_exists, Name, node()}}
-    end;
-tm_prepare(Cp) when is_record(Cp, checkpoint) ->
-    %% Node with old protocol sent an old checkpoint record
-    %% and we have to convert it
-    case convert_cp_record(Cp) of
-	{ok, NewCp} ->
-	    tm_prepare(NewCp);
-	{error, Reason} ->
-	    {error, Reason}
     end.
 
 tm_mnesia_down(Node) ->
@@ -156,7 +128,8 @@ tm_enter_pending(Pending) ->
 tm_enter_pending([], Pending) ->
     Pending;
 tm_enter_pending([Tab | Tabs], Pending) ->
-    catch ?ets_insert(Tab, Pending),
+    %% io:format("Add ~p ~p ~p~n",[Tab, Pending, hd(tl(element(2, process_info(self(), current_stacktrace))))]),
+    ?SAFE(?ets_insert(Tab, Pending)),
     tm_enter_pending(Tabs, Pending).
 
 tm_exit_pending(Tid) ->
@@ -371,9 +344,7 @@ activate(Args) ->
     end.
 
 args2cp(Args) when is_list(Args)->
-    case catch lists:foldl(fun check_arg/2, #checkpoint_args{}, Args) of
-	{'EXIT', Reason} ->
-	    {error, Reason};
+    try lists:foldl(fun check_arg/2, #checkpoint_args{}, Args) of
 	Cp ->
 	    case check_tables(Cp) of
 		{error, Reason} ->
@@ -381,6 +352,10 @@ args2cp(Args) when is_list(Args)->
 		{ok, Overriders, AllTabs} ->
 		    arrange_retainers(Cp, Overriders, AllTabs)
 	    end
+    catch exit:Reason ->
+	    {error, Reason};
+	  error:Reason ->
+	    {error, Reason}
     end;
 args2cp(Args) ->
     {error, {badarg, Args}}.
@@ -390,10 +365,10 @@ check_arg({name, Name}, Cp) ->
 	true ->
 	    exit({already_exists, Name});
 	false ->
-	    case catch tab2retainer({foo, Name}) of
-		List when is_list(List) ->
-		    Cp#checkpoint_args{name = Name};
-		_ ->
+	    try
+		[_|_] = tab2retainer({foo, Name}),
+		Cp#checkpoint_args{name = Name}
+	    catch _:_ ->
 		    exit({badarg, Name})
 	    end
     end;
@@ -453,22 +428,22 @@ check_tables(Cp) ->
 
 arrange_retainers(Cp, Overriders, AllTabs) ->
     R = #retainer{cp_name = Cp#checkpoint_args.name},
-    case catch [R#retainer{tab_name = Tab, 
-			   writers = select_writers(Cp, Tab)}
-		|| Tab <- AllTabs] of
-	{'EXIT', Reason} ->
-	    {error, Reason};
+    try [R#retainer{tab_name = Tab,
+		    writers = select_writers(Cp, Tab)}
+	 || Tab <- AllTabs] of
 	Retainers ->
 	    {ok, Cp#checkpoint_args{ram_overrides_dump = Overriders,
-			       retainers = Retainers,
-			       nodes = writers(Retainers)}}
+				    retainers = Retainers,
+				    nodes = writers(Retainers)}}
+    catch throw:Reason ->
+	    {error, Reason}
     end.
 
 select_writers(Cp, Tab) ->
     case filter_remote(Cp, val({Tab, active_replicas})) of
 	[] ->
-	    exit({"Cannot prepare checkpoint (replica not available)",
-		 [Tab, Cp#checkpoint_args.name]});
+	    throw({"Cannot prepare checkpoint (replica not available)",
+		   [Tab, Cp#checkpoint_args.name]});
 	Writers ->
 	    This = node(),
 	    case {lists:member(Tab, Cp#checkpoint_args.max),
@@ -518,12 +493,12 @@ check_prep([], Name, Nodes, IgnoreNew) ->
 collect_pending(Name, Nodes, IgnoreNew) ->
     case rpc:multicall(Nodes, ?MODULE, call, [Name, collect_pending]) of
 	{Replies, []} ->
-	    case catch ?ets_new_table(mnesia_union, [bag]) of
-		{'EXIT', Reason} -> %% system limit
+	    try
+		UnionTab = ?ets_new_table(mnesia_union, [bag]),
+		compute_union(Replies, Nodes, Name, UnionTab, IgnoreNew)
+	    catch error:Reason -> %% system limit
 		    Msg = "Cannot create an ets table pending union",
-		    {error, {system_limit, Msg, Reason}};
-		UnionTab ->
-		    compute_union(Replies, Nodes, Name, UnionTab, IgnoreNew)
+		    {error, {system_limit, Msg, Reason}}
 	    end;
 	{_, BadNodes} ->
 	    deactivate(Nodes, Name),
@@ -641,11 +616,7 @@ init(Cp) ->
     process_flag(priority, high), %% Needed dets files might starve the system
     Name = Cp#checkpoint_args.name,
     Props = [set, public, {keypos, 2}],
-    case catch ?ets_new_table(mnesia_pending_checkpoint, Props) of
-	{'EXIT', Reason} -> %% system limit
-	    Msg = "Cannot create an ets table for pending transactions",
-	    Error = {error, {system_limit, Name, Msg, Reason}},
-	    proc_lib:init_ack(Cp#checkpoint_args.supervisor, Error);
+    try ?ets_new_table(mnesia_pending_checkpoint, Props) of
 	PendingTab ->
 	    Rs = [prepare_tab(Cp, R) || R <- Cp#checkpoint_args.retainers],
 	    Cp2 = Cp#checkpoint_args{retainers = Rs,
@@ -658,6 +629,10 @@ init(Cp) ->
 	    dbg_out("Checkpoint ~p (~p) started~n", [Name, self()]),
 	    proc_lib:init_ack(Cp2#checkpoint_args.supervisor, {ok, self()}),
 	    retainer_loop(Cp2)
+    catch error:Reason -> %% system limit
+	    Msg = "Cannot create an ets table for pending transactions",
+	    Error = {error, {system_limit, Name, Msg, Reason}},
+	    proc_lib:init_ack(Cp#checkpoint_args.supervisor, Error)
     end.
     
 prepare_tab(Cp, R) ->
@@ -700,6 +675,16 @@ tab2retainer({Tab, Name}) ->
     FlatName = lists:flatten(io_lib:write(Name)),
     mnesia_lib:dir(lists:concat([?MODULE, "_", Tab, "_", FlatName, ".RET"])).
 
+retainer_create(_Cp, R, Tab, Name, Ext = {ext, Alias, Mod}) ->
+    T = {Tab, retainer, Name},
+    P = mnesia_schema:cs2list(val({Tab, cstruct})),
+    Mod:delete_table(Alias, T),
+    ok = Mod:create_table(Alias, T, P),
+    Cs = val({Tab, cstruct}),
+    Mod:load_table(Alias, T, {retainer, create_table},
+		   mnesia_schema:cs2list(Cs)),
+    dbg_out("Checkpoint retainer created ~p ~p~n", [Name, Tab]),
+    R#retainer{store = {Ext, T}, really_retain = true};
 retainer_create(_Cp, R, Tab, Name, disc_only_copies) ->
     Fname = tab2retainer({Tab, Name}),
     file:delete(Fname),
@@ -759,15 +744,23 @@ traverse_dcd({Cont, Recs}, Log, Fun) ->     %% trashed data??
 traverse_dcd(eof, _Log, _Fun) ->
     ok.
 
+retainer_get({{ext, Alias, Mod}, Store}, Key) ->
+    Mod:lookup(Alias, Store, Key);
 retainer_get({ets, Store}, Key) -> ?ets_lookup(Store, Key);
 retainer_get({dets, Store}, Key) -> dets:lookup(Store, Key).
 
+retainer_put({{ext, Alias, Mod}, Store}, Val) ->
+    Mod:insert(Alias, Store, Val);
 retainer_put({ets, Store}, Val) -> ?ets_insert(Store, Val);
 retainer_put({dets, Store}, Val) -> dets:insert(Store, Val).
 
+retainer_first({{ext, Alias, Mod}, Store}) ->
+    Mod:first(Alias, Store);
 retainer_first({ets, Store}) -> ?ets_first(Store);
 retainer_first({dets, Store}) -> dets:first(Store).
  
+retainer_next({{ext, Alias, Mod}, Store}, Key) ->
+    Mod:next(Alias, Store, Key);
 retainer_next({ets, Store}, Key) -> ?ets_next(Store, Key);
 retainer_next({dets, Store}, Key) -> dets:next(Store, Key).
 
@@ -786,11 +779,16 @@ retainer_next({dets, Store}, Key) -> dets:next(Store, Key).
 
 retainer_fixtable(Tab, Bool) when is_atom(Tab) ->
     mnesia_lib:db_fixtable(val({Tab, storage_type}), Tab, Bool);
+retainer_fixtable({Ext = {ext, _, _}, Tab}, Bool) ->
+    mnesia_lib:db_fixtable(Ext, Tab, Bool);
 retainer_fixtable({ets, Tab}, Bool) ->
     mnesia_lib:db_fixtable(ram_copies, Tab, Bool);
 retainer_fixtable({dets, Tab}, Bool) ->
     mnesia_lib:db_fixtable(disc_only_copies, Tab, Bool).
 
+retainer_delete({{ext, Alias, Mod}, Store}) ->
+    Mod:close_table(Alias, Store),
+    Mod:delete_table(Alias, Store);
 retainer_delete({ets, Store}) ->
     ?ets_delete_table(Store);
 retainer_delete({dets, Store}) ->
@@ -798,104 +796,142 @@ retainer_delete({dets, Store}) ->
     Fname = tab2retainer(Store),
     file:delete(Fname).
 
-retainer_loop(Cp) ->
-    Name = Cp#checkpoint_args.name,
+retainer_loop(Cp = #checkpoint_args{is_activated=false, name=Name}) ->
     receive
-	{_From, {retain, Tid, Tab, Key, OldRecs}}
-	when Cp#checkpoint_args.wait_for_old == [] ->
-	    R = val({Tab, {retainer, Name}}),
-	    PendingTab = Cp#checkpoint_args.pending_tab,
-	    case R#retainer.really_retain of
-		true when PendingTab =:= undefined ->
-		    Store = R#retainer.store,
-		    case retainer_get(Store, Key) of
-			[] ->  retainer_put(Store, {Tab, Key, OldRecs});
-			_ ->   already_retained
-		    end;
-		true ->
-		    case ets:member(PendingTab, Tid) of
-			true -> ignore;
-			false -> 
-			    Store = R#retainer.store,
-			    case retainer_get(Store, Key) of
-				[] ->  retainer_put(Store, {Tab, Key, OldRecs});
-				_ ->   already_retained
-			    end			
-		    end;
-		false ->
-		    ignore
-	    end,
-	    retainer_loop(Cp);
-	
 	%% Adm
+	{From, {activate, Pending}} ->
+            StillPending = mnesia_recover:still_pending(Pending),
+            enter_still_pending(StillPending, Cp#checkpoint_args.pending_tab),
+	    Local = [Tid || #tid{pid=Pid} = Tid <- StillPending, node(Pid) =/= node()],
+            Cp2 = maybe_activate(Cp#checkpoint_args{wait_for_old = Local}),
+
+            reply(From, Name, activated),
+	    retainer_loop(Cp2);
+
+	{_From, {exit_pending, Tid}} when is_list(Cp#checkpoint_args.wait_for_old) ->
+	    StillPending = lists:delete(Tid, Cp#checkpoint_args.wait_for_old),
+	    Cp2 = Cp#checkpoint_args{wait_for_old = StillPending},
+	    Cp3 = maybe_activate(Cp2),
+	    retainer_loop(Cp3);
+
 	{From, deactivate} ->
 	    do_stop(Cp),
 	    reply(From, Name, deactivated),
 	    unlink(From),
 	    exit(shutdown);
 
+	{From, get_checkpoint} ->
+	    reply(From, Name, Cp),
+	    retainer_loop(Cp);
+	{_From, {add_retainer, R, Node}} ->
+	    Cp2 = do_add_retainer(Cp, R, Node),
+	    retainer_loop(Cp2);
+
+	{From, collect_pending} ->
+	    PendingTab = Cp#checkpoint_args.pending_tab,
+	    del(pending_checkpoints, PendingTab),
+	    Pending = ?ets_match_object(PendingTab, '_'),
+	    reply(From, Name, {ok, Pending}),
+	    retainer_loop(Cp);
+
+	{_From, {mnesia_down, Node}} ->
+	    Cp2 = do_del_retainers(Cp, Node),
+	    retainer_loop(Cp2);
+
 	{'EXIT', Parent, _} when Parent == Cp#checkpoint_args.supervisor ->
 	    %% do_stop(Cp),
 	    %% assume that entire Mnesia is terminating
 	    exit(shutdown);
 
-	{_From, {mnesia_down, Node}} ->
-	    Cp2 = do_del_retainers(Cp, Node),
-	    retainer_loop(Cp2);
+	{'EXIT', From, _Reason} ->
+	    Iters = [Iter || Iter <- Cp#checkpoint_args.iterators,
+			     check_iter(From, Iter)],
+	    retainer_loop(Cp#checkpoint_args{iterators = Iters});
+
+	{system, From, Msg} ->
+	    dbg_out("~p got {system, ~p, ~p}~n", [?MODULE, From, Msg]),
+	    sys:handle_system_msg(Msg, From, Cp#checkpoint_args.supervisor,
+				  ?MODULE, [], Cp)
+    end;
+
+retainer_loop(Cp = #checkpoint_args{name=Name}) ->
+    receive
+	{_From, {retain, Tid, Tab, Key, OldRecs}} ->
+	    R = val({Tab, {retainer, Name}}),
+	    PendingTab = Cp#checkpoint_args.pending_tab,
+	    case R#retainer.really_retain of
+		true ->
+		    Store = R#retainer.store,
+		    try true = ets:member(PendingTab, Tid),
+			 %% io:format("CP: ~p ~p ~p ~p~n",[true, Tab, Key, Tid]),
+			 case retainer_get(Store, Key) of
+			     [] -> ignore;
+			     _  -> ets:delete(element(2,Store), Key)
+			 end
+		    catch _:_ ->
+			    %% io:format("CP: ~p ~p ~p ~p~n",[false, Tab, Key, Tid]),
+			    case retainer_get(Store, Key) of
+				[] -> retainer_put(Store, {Tab, Key, OldRecs});
+				_  -> already_retained
+			    end
+		    end;
+		false ->
+		    ignore
+	    end,
+	    retainer_loop(Cp);
+
+	%% Adm
 	{From, get_checkpoint} ->
 	    reply(From, Name, Cp),
 	    retainer_loop(Cp);
-	{From, {add_copy, Tab, Node}} when Cp#checkpoint_args.wait_for_old == [] ->
+	{From, {add_copy, Tab, Node}} ->
 	    {Res, Cp2} = do_add_copy(Cp, Tab, Node),
 	    reply(From, Name, Res),
 	    retainer_loop(Cp2);
-	{From, {del_copy, Tab, Node}} when Cp#checkpoint_args.wait_for_old == [] ->
+	{From, {del_copy, Tab, Node}} ->
 	    Cp2 = do_del_copy(Cp, Tab, Node),
 	    reply(From, Name, ok),
 	    retainer_loop(Cp2);
-	{From, {change_copy, Tab, From, To}} when Cp#checkpoint_args.wait_for_old == [] ->
+	{From, {change_copy, Tab, From, To}} ->
 	    Cp2 = do_change_copy(Cp, Tab, From, To),
 	    reply(From, Name, ok),
 	    retainer_loop(Cp2);
 	{_From, {add_retainer, R, Node}} ->
 	    Cp2 = do_add_retainer(Cp, R, Node),
 	    retainer_loop(Cp2);
-	{_From, {del_retainer, R, Node}} when Cp#checkpoint_args.wait_for_old == [] ->
+	{_From, {del_retainer, R, Node}} ->
 	    Cp2 = do_del_retainer(Cp, R, Node),
 	    retainer_loop(Cp2);
 
 	%% Iteration
-	{From, {iter_begin, Iter}} when Cp#checkpoint_args.wait_for_old == [] ->
+	{From, {iter_begin, Iter}} ->
 	    Cp2 = iter_begin(Cp, From, Iter),
 	    retainer_loop(Cp2);
 
-	{From, {iter_end, Iter}} when Cp#checkpoint_args.wait_for_old == [] ->
+	{From, {iter_end, Iter}}  ->
 	    retainer_fixtable(Iter#iter.oid_tab, false),
 	    Iters = Cp#checkpoint_args.iterators -- [Iter],
 	    reply(From, Name, ok),
-	    retainer_loop(Cp#checkpoint_args{iterators = Iters});	
-
-	{_From, {exit_pending, Tid}}
-	    when is_list(Cp#checkpoint_args.wait_for_old) ->
-	    StillPending = lists:delete(Tid, Cp#checkpoint_args.wait_for_old),
-	    Cp2 = Cp#checkpoint_args{wait_for_old = StillPending},
-	    Cp3 = maybe_activate(Cp2),
-	    retainer_loop(Cp3);
+	    retainer_loop(Cp#checkpoint_args{iterators = Iters});
 
-	{From, collect_pending} ->
-	    PendingTab = Cp#checkpoint_args.pending_tab,
-	    del(pending_checkpoints, PendingTab),
-	    Pending = ?ets_match_object(PendingTab, '_'),
-	    reply(From, Name, {ok, Pending}),
+	{_From, {exit_pending, _Tid}} ->
 	    retainer_loop(Cp);
 
-	{From, {activate, Pending}} ->
-            StillPending = mnesia_recover:still_pending(Pending),
-            enter_still_pending(StillPending, Cp#checkpoint_args.pending_tab),
-            Cp2 = maybe_activate(Cp#checkpoint_args{wait_for_old = StillPending}),
-            reply(From, Name, activated),
+	{From, deactivate} ->
+	    do_stop(Cp),
+	    reply(From, Name, deactivated),
+	    unlink(From),
+	    exit(shutdown);
+
+	{_From, {mnesia_down, Node}} ->
+	    Cp2 = do_del_retainers(Cp, Node),
 	    retainer_loop(Cp2);
 
+	{'EXIT', Parent, _} when Parent == Cp#checkpoint_args.supervisor ->
+	    %% do_stop(Cp),
+	    %% assume that entire Mnesia is terminating
+	    exit(shutdown);
+
 	{'EXIT', From, _Reason} ->
 	    Iters = [Iter || Iter <- Cp#checkpoint_args.iterators,
 			     check_iter(From, Iter)],
@@ -903,13 +939,17 @@ retainer_loop(Cp) ->
 
 	{system, From, Msg} ->
 	    dbg_out("~p got {system, ~p, ~p}~n", [?MODULE, From, Msg]),
-	    sys:handle_system_msg(Msg, From, no_parent, ?MODULE, [], Cp)
+	    sys:handle_system_msg(Msg, From, Cp#checkpoint_args.supervisor,
+				  ?MODULE, [], Cp);
+	Msg ->
+	    dbg_out("~p got ~p~n", [?MODULE, Msg])
     end.
 
 maybe_activate(Cp)
-        when Cp#checkpoint_args.wait_for_old == [],
-             Cp#checkpoint_args.is_activated == false ->
-    Cp#checkpoint_args{pending_tab = undefined, is_activated = true};
+  when Cp#checkpoint_args.wait_for_old == [],
+       Cp#checkpoint_args.is_activated == false ->
+    Cp#checkpoint_args{%% pending_tab = undefined,
+		       is_activated = true};
 maybe_activate(Cp) ->
     Cp.
 
@@ -1154,7 +1194,7 @@ iterate(Name, Tab, Fun, Acc, Source, Val) ->
 	    {error, Reason};
 	{ok, Iter, Pid} ->
 	    link(Pid), % We don't want any pending fixtable's
-	    Res = (catch iter(Fun, Acc, Iter)),
+	    Res = ?CATCH(iter(Fun, Acc, Iter)),
 	    unlink(Pid),
 	    call(Name, {iter_end, Iter}),
 	    case Res of
@@ -1226,70 +1266,11 @@ system_terminate(_Reason, _Parent,_Debug, Cp) ->
 system_code_change(Cp, _Module, _OldVsn, _Extra) ->
     {ok, Cp}.
 
-convert_cp_record(Cp) when is_record(Cp, checkpoint) ->
-    ROD = 
-	case Cp#checkpoint.ram_overrides_dump of
-	    true -> Cp#checkpoint.min ++ Cp#checkpoint.max;
-	    false -> []
-	end,
-
-    {ok, #checkpoint_args{name = Cp#checkpoint.name,
-			  allow_remote = Cp#checkpoint.name,
-			  ram_overrides_dump = ROD,
-			  nodes = Cp#checkpoint.nodes,
-			  node = Cp#checkpoint.node,
-			  now = Cp#checkpoint.now,
-			  cookie = ?unique_cookie,
-			  min = Cp#checkpoint.min,
-			  max = Cp#checkpoint.max,
-			  pending_tab = Cp#checkpoint.pending_tab,
-			  wait_for_old = Cp#checkpoint.wait_for_old,
-			  is_activated = Cp#checkpoint.is_activated,
-			  ignore_new = Cp#checkpoint.ignore_new,
-			  retainers = Cp#checkpoint.retainers,
-			  iterators = Cp#checkpoint.iterators,
-			  supervisor = Cp#checkpoint.supervisor,
-			  pid = Cp#checkpoint.pid
-			 }};
-convert_cp_record(Cp) when is_record(Cp, checkpoint_args) ->
-    AllTabs = Cp#checkpoint_args.min ++ Cp#checkpoint_args.max,
-    ROD = case Cp#checkpoint_args.ram_overrides_dump of
-	      [] -> 
-		  false;
-	      AllTabs -> 
-		  true;
-	      _ -> 
-		  error
-	  end,
-    if
-	ROD == error ->
-	    {error, {"Old node cannot handle new checkpoint protocol",
-		     ram_overrides_dump}};
-	true ->
-	    {ok, #checkpoint{name = Cp#checkpoint_args.name,
-			     allow_remote = Cp#checkpoint_args.name,
-			     ram_overrides_dump = ROD,
-			     nodes = Cp#checkpoint_args.nodes,
-			     node = Cp#checkpoint_args.node,
-			     now = Cp#checkpoint_args.now,
-			     min = Cp#checkpoint_args.min,
-			     max = Cp#checkpoint_args.max,
-			     pending_tab = Cp#checkpoint_args.pending_tab,
-			     wait_for_old = Cp#checkpoint_args.wait_for_old,
-			     is_activated = Cp#checkpoint_args.is_activated,
-			     ignore_new = Cp#checkpoint_args.ignore_new,
-			     retainers = Cp#checkpoint_args.retainers,
-			     iterators = Cp#checkpoint_args.iterators,
-			     supervisor = Cp#checkpoint_args.supervisor,
-			     pid = Cp#checkpoint_args.pid
-			    }}
-    end.
-
 %%%%%%%%%%%%%%%%%%%%%%%%%%
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', _ReASoN_} -> mnesia_lib:other_val(Var, _ReASoN_); 
-	_VaLuE_ -> _VaLuE_ 
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
+	_VaLuE_ -> _VaLuE_
     end.
 
diff --git a/lib/mnesia/src/mnesia_checkpoint_sup.erl b/lib/mnesia/src/mnesia_checkpoint_sup.erl
index 2fe8df52f7..ae3f77f37e 100644
--- a/lib/mnesia/src/mnesia_checkpoint_sup.erl
+++ b/lib/mnesia/src/mnesia_checkpoint_sup.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_controller.erl b/lib/mnesia/src/mnesia_controller.erl
index 78f7bfa325..4791e2e290 100644
--- a/lib/mnesia/src/mnesia_controller.erl
+++ b/lib/mnesia/src/mnesia_controller.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -51,6 +52,7 @@
 	 force_load_table/1,
 	 async_dump_log/1,
 	 sync_dump_log/1,
+	 snapshot_dcd/1,
 	 connect_nodes/1,
          connect_nodes/2,
 	 wait_for_schema_commit_lock/0,
@@ -76,7 +78,7 @@
 	 change_table_majority/1,
 	 del_active_replica/2,
 	 wait_for_tables/2,
-	 get_network_copy/2,
+	 get_network_copy/3,
 	 merge_schema/0,
 	 start_remote_sender/4,
 	 schedule_late_disc_load/2
@@ -139,7 +141,8 @@ max_loaders() ->
 -record(block_controller, {owner}).
 
 -record(dump_log, {initiated_by,
-		   opt_reply_to
+		   opt_reply_to,
+		   operation = dump_log
 		  }).
 
 -record(net_load, {table,
@@ -184,7 +187,7 @@ max_loaders() ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason);
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
 	Value -> Value
     end.
 
@@ -198,7 +201,17 @@ sync_dump_log(InitBy) ->
     call({sync_dump_log, InitBy}).
 
 async_dump_log(InitBy) ->
-    ?SERVER_NAME ! {async_dump_log, InitBy}.
+    ?SERVER_NAME ! {async_dump_log, InitBy},
+    ok.
+
+snapshot_dcd(Tables) when is_list(Tables) ->
+    case [T || T <- Tables,
+	       mnesia_lib:storage_type_at_node(node(), T) =/= disc_copies] of
+	[] ->
+	    call({snapshot_dcd, Tables});
+	BadTabs ->
+	    {error, {not_disc_copies, BadTabs}}
+    end.
 
 %% Wait for tables to be active
 %% If needed, we will wait for Mnesia to start
@@ -229,9 +242,7 @@ do_wait_for_tables(Tabs, Timeout) ->
     end.
 
 reply_wait(Tabs) ->
-    case catch mnesia_lib:active_tables() of
-	{'EXIT', _} ->
-	    {error, {node_not_running, node()}};
+    try mnesia_lib:active_tables() of
 	Active when is_list(Active) ->
 	    case Tabs -- Active of
 		[] ->
@@ -239,6 +250,7 @@ reply_wait(Tabs) ->
 		BadTabs ->
 		    {timeout, BadTabs}
 	    end
+    catch exit:_ -> {error, {node_not_running, node()}}
     end.
 
 wait_for_tables_init(From, Tabs) ->
@@ -249,13 +261,12 @@ wait_for_tables_init(From, Tabs) ->
     exit(normal).
 
 wait_for_init(From, Tabs, Init) ->
-    case catch link(Init) of
-	{'EXIT', _} ->
-	    %% Mnesia is not started
-	    {error, {node_not_running, node()}};
+    try link(Init) of
 	true when is_pid(Init) ->
 	    cast({sync_tabs, Tabs, self()}),
 	    rec_tabs(Tabs, Tabs, From, Init)
+    catch error:_ -> %% Mnesia is not started
+	    {error, {node_not_running, node()}}
     end.
 
 sync_reply(Waiter, Tab) ->
@@ -293,13 +304,19 @@ update(Fun) ->
 
 
 mnesia_down(Node) ->
-    case cast({mnesia_down, Node}) of
-	{error, _} -> mnesia_monitor:mnesia_down(?SERVER_NAME, Node);
-	_Pid ->  ok
+    case whereis(?SERVER_NAME) of
+	undefined -> mnesia_monitor:mnesia_down(?SERVER_NAME, Node);
+	Pid -> gen_server:cast(Pid, {mnesia_down, Node})
     end.
+
 wait_for_schema_commit_lock() ->
-    link(whereis(?SERVER_NAME)),
-    unsafe_call(wait_for_schema_commit_lock).
+    try
+	Pid = whereis(?SERVER_NAME),
+	link(Pid), %% Keep the link until release_schema_commit_lock
+	gen_server:call(Pid, wait_for_schema_commit_lock, infinity)
+    catch _:_ ->
+	    mnesia:abort({node_not_running, node()})
+    end.
 
 block_controller() ->
     call(block_controller).
@@ -312,20 +329,20 @@ release_schema_commit_lock() ->
     unlink(whereis(?SERVER_NAME)).
 
 %% Special for preparation of add table copy
-get_network_copy(Tab, Cs) ->
+get_network_copy(Tid, Tab, Cs) ->
 %   We can't let the controller queue this one
 %   because that may cause a deadlock between schema_operations
 %   and initial tableloadings which both takes schema locks.
 %   But we have to get copier_done msgs when the other side
 %   goes down.
     call({add_other, self()}),
-    Reason = {dumper,add_table_copy},
+    Reason = {dumper,{add_table_copy, Tid}},
     Work = #net_load{table = Tab,reason = Reason,cstruct = Cs},
     %% I'll need this cause it's linked trough the subscriber
     %% might be solved by using monitor in subscr instead.
     process_flag(trap_exit, true),
     Load = load_table_fun(Work),
-    Res = (catch Load()),
+    Res = ?CATCH(Load()),
     process_flag(trap_exit, false),
     call({del_other, self()}),
     case Res of
@@ -368,6 +385,8 @@ force_load_table(Tab) when is_atom(Tab), Tab /= schema ->
 	    do_force_load_table(Tab);
 	disc_only_copies ->
 	    do_force_load_table(Tab);
+        {ext, _, _} ->
+            do_force_load_table(Tab);
 	unknown ->
 	    set({Tab, load_by_force}, true),
 	    cast({force_load_updated, Tab}),
@@ -467,7 +486,7 @@ connect_nodes2(Father, Ns, UserFun) ->
     process_flag(trap_exit, true),
     Res = try_merge_schema(New, [], UserFun),
     Msg = {schema_is_merged, [], late_merge, []},
-    multicall([node()|Ns], Msg),
+    _ = multicall([node()|Ns], Msg),
     After = val({current, db_nodes}),
     Father ! {?MODULE, self(), Res, mnesia_lib:intersect(Ns,After)},
     unlink(Father),
@@ -548,19 +567,13 @@ schema_is_merged() ->
 
 cast(Msg) ->
     case whereis(?SERVER_NAME) of
-	undefined ->{error, {node_not_running, node()}};
+	undefined -> ok;
 	Pid ->  gen_server:cast(Pid, Msg)
     end.
 
 abcast(Nodes, Msg) ->
     gen_server:abcast(Nodes, ?SERVER_NAME, Msg).
 
-unsafe_call(Msg) ->
-    case whereis(?SERVER_NAME) of
-	undefined -> {error, {node_not_running, node()}};
-	Pid -> gen_server:call(Pid, Msg, infinity)
-    end.
-
 call(Msg) ->
     case whereis(?SERVER_NAME) of
 	undefined ->
@@ -580,11 +593,8 @@ call(Msg) ->
     end.
 
 remote_call(Node, Func, Args) ->
-    case catch gen_server:call({?MODULE, Node}, {Func, Args, self()}, infinity) of
-	{'EXIT', Error} ->
-	    {error, Error};
-	Else ->
-	    Else
+    try gen_server:call({?MODULE, Node}, {Func, Args, self()}, infinity)
+    catch exit:Error -> {error, Error}
     end.
 
 multicall(Nodes, Msg) ->
@@ -645,6 +655,15 @@ handle_call({sync_dump_log, InitBy}, From, State) ->
     State2 = add_worker(Worker, State),
     noreply(State2);
 
+handle_call({snapshot_dcd, Tables}, From, State) ->
+    Worker = #dump_log{initiated_by = user,
+		       opt_reply_to = From,
+		       operation = fun() ->
+					   mnesia_dumper:snapshot_dcd(Tables)
+				   end},
+    State2 = add_worker(Worker, State),
+    noreply(State2);
+
 handle_call(wait_for_schema_commit_lock, From, State) ->
     Worker = #schema_commit_lock{owner = From},
     State2 = add_worker(Worker, State),
@@ -656,7 +675,7 @@ handle_call(block_controller, From, State) ->
     noreply(State2);
 
 handle_call({update,Fun}, From, State) ->
-    Res = (catch Fun()),
+    Res = ?CATCH(Fun()),
     reply(From, Res),
     noreply(State);
 
@@ -758,7 +777,7 @@ handle_call({net_load, Tab, Cs}, From, State) ->
 	    true ->
 		Worker = #net_load{table = Tab,
 				   opt_reply_to = From,
-				   reason = {dumper,add_table_copy},
+				   reason = {dumper,{add_table_copy, unknown}},
 				   cstruct = Cs
 				  },
 		add_worker(Worker, State);
@@ -1163,11 +1182,11 @@ handle_info(Done = #loader_done{worker_pid=WPid, table_name=Tab}, State0) ->
 		    Done#loader_done.needs_announce == true,
 		    Done#loader_done.needs_reply == true ->
 			i_have_tab(Tab),
-			%% Should be {dumper,add_table_copy} only
+			%% Should be {dumper,{add_table_copy, _}} only
 			reply(Done#loader_done.reply_to,
 			      Done#loader_done.reply);
 		    Done#loader_done.needs_reply == true ->
-			%% Should be {dumper,add_table_copy} only
+			%% Should be {dumper,{add_table_copy,_}} only
 			reply(Done#loader_done.reply_to,
 			      Done#loader_done.reply);
 		    Done#loader_done.needs_announce == true, Tab == schema ->
@@ -1206,7 +1225,14 @@ handle_info(Done = #loader_done{worker_pid=WPid, table_name=Tab}, State0) ->
 			{value,{_,Worker}} = lists:keysearch(WPid,1,get_loaders(State0)),
 			add_loader(Tab,Worker,State1);
 		    _ ->
-			State1
+			DelState = State1#state{late_loader_queue=gb_trees:delete_any(Tab, LateQueue0)},
+			case ?catch_val({Tab, storage_type}) of
+			    ram_copies ->
+				cast({disc_load, Tab, ram_only}),
+				DelState;
+			    _ ->
+				DelState
+			end
 		end
 	end,
     State3 = opt_start_worker(State2),
@@ -1228,7 +1254,7 @@ handle_info(#sender_done{worker_pid=Pid, worker_res=Res}, State)  ->
     end;
 
 handle_info({'EXIT', Pid, R}, State) when Pid == State#state.supervisor ->
-    catch set(mnesia_status, stopping),
+    ?SAFE(set(mnesia_status, stopping)),
     case State#state.dumper_pid of
 	undefined ->
 	    dbg_out("~p was ~p~n", [?SERVER_NAME, R]),
@@ -1452,9 +1478,9 @@ orphan_tables([], _, _, LocalOrphans, RemoteMasters) ->
 
 node_has_tabs([Tab | Tabs], Node, State) when Node /= node() ->
     State2 =
-	case catch update_whereabouts(Tab, Node, State) of
-	    State1 = #state{} -> State1;
-	    {'EXIT', R} ->  %% Tab was just deleted?
+	try update_whereabouts(Tab, Node, State) of
+	    State1 = #state{} -> State1
+	catch exit:R -> %% Tab was just deleted?
 		case ?catch_val({Tab, cstruct}) of
 		    {'EXIT', _} -> State; % yes
 		    _ ->  erlang:error(R)
@@ -1509,8 +1535,8 @@ update_whereabouts(Tab, Node, State) ->
 	Storage == unknown ->
 	    %% No own copy, continue to read remotely
 	    add_active_replica(Tab, Node),
-	    NodeST = mnesia_lib:storage_type_at_node(Node, Tab),
-	    ReadST = mnesia_lib:storage_type_at_node(Read, Tab),
+	    NodeST = mnesia_lib:semantics(mnesia_lib:storage_type_at_node(Node, Tab), storage),
+	    ReadST = mnesia_lib:semantics(mnesia_lib:storage_type_at_node(Read, Tab), storage),
 	    if   %% Avoid reading from disc_only_copies
 		NodeST == disc_only_copies ->
 		    ignore;
@@ -1564,6 +1590,7 @@ last_consistent_replica(Tab, Downs) ->
     Ram = Cs#cstruct.ram_copies,
     Disc = Cs#cstruct.disc_copies,
     DiscOnly = Cs#cstruct.disc_only_copies,
+    Ext = Cs#cstruct.external_copies,
     BetterCopies0 = mnesia_lib:remote_copy_holders(Cs) -- Downs,
     BetterCopies = BetterCopies0 -- Ram,
     AccessMode = Cs#cstruct.access_mode,
@@ -1596,7 +1623,7 @@ last_consistent_replica(Tab, Downs) ->
 	    false;
 	Storage == ram_copies ->
 	    if
-		Disc == [], DiscOnly == [] ->
+		Disc == [], DiscOnly == [], Ext == [] ->
 		    %% Nobody has copy on disc
 		    {true, {Tab, ram_only}};
 		true ->
@@ -1740,22 +1767,17 @@ change_table_majority(Cs) ->
 
 update_where_to_wlock(Tab) ->
     WNodes = val({Tab, where_to_write}),
-    Majority = case catch val({Tab, majority}) of
-		   true -> true;
-		   _    -> false
-	       end,
+    Majority = ?catch_val({Tab, majority}) == true,
     set({Tab, where_to_wlock}, {WNodes, Majority}).
 
 %% node To now has tab loaded, but this must be undone
 %% This code is rpc:call'ed from the tab_copier process
 %% when it has *not* released it's table lock
 unannounce_add_table_copy(Tab, To) ->
-    catch del_active_replica(Tab, To),
-    case catch val({Tab , where_to_read}) of
-	To ->
-	    mnesia_lib:set_remote_where_to_read(Tab);
-	_ ->
-	    ignore
+    ?SAFE(del_active_replica(Tab, To)),
+    try To = val({Tab , where_to_read}),
+	 mnesia_lib:set_remote_where_to_read(Tab)
+    catch _:_ -> ignore
     end.
 
 user_sync_tab(Tab) ->
@@ -1789,7 +1811,7 @@ sync_and_block_table_whereabouts(Tab, ToNode, RemoteS, AccessMode) when Tab /= s
 	    true -> Current -- [ToNode];
 	    false -> Current
 	end,
-    remote_call(ToNode, block_table, [Tab]),
+    _ = remote_call(ToNode, block_table, [Tab]),
     [remote_call(Node, add_active_replica, [Tab, ToNode, RemoteS, AccessMode]) ||
 	Node <- [ToNode | Ns]],
     ok.
@@ -1846,6 +1868,11 @@ info([Tab | Tail]) ->
 			dets:info(Tab, size),
 			dets:info(Tab, file_size),
 			"bytes on disc");
+        {ext, Alias, Mod} ->
+            info_format(Tab,
+                        Mod:info(Alias, Tab, size),
+                        Mod:info(Alias, Tab, memory),
+                        "words of mem");
 	_ ->
 	    info_format(Tab,
 			?ets_info(Tab, size),
@@ -2081,7 +2108,12 @@ start_remote_sender(Node, Tab, Receiver, Storage) ->
 
 dump_and_reply(ReplyTo, Worker) ->
     %% No trap_exit, die intentionally instead
-    Res = mnesia_dumper:opt_dump_log(Worker#dump_log.initiated_by),
+    Res = case Worker#dump_log.operation of
+	      dump_log ->
+		  mnesia_dumper:opt_dump_log(Worker#dump_log.initiated_by);
+	      F when is_function(F, 0) ->
+		  F()
+	  end,
     ReplyTo ! #dumper_done{worker_pid = self(),
 			   worker_res = Res},
     unlink(ReplyTo),
@@ -2124,6 +2156,10 @@ load_table_fun(#net_load{cstruct=Cs, table=Tab, reason=Reason, opt_reply_to=Repl
 			reply_to = ReplyTo,
 			reply = {loaded, ok}
 		       },
+    AddTableCopy = case Reason of
+		       {dumper,{add_table_copy,_}} -> true;
+		       _ -> false
+		   end,
     if
 	ReadNode == node() ->
 	    %% Already loaded locally
@@ -2133,7 +2169,7 @@ load_table_fun(#net_load{cstruct=Cs, table=Tab, reason=Reason, opt_reply_to=Repl
 		    Res = mnesia_loader:disc_load_table(Tab, load_local_content),
 		    Done#loader_done{reply = Res, needs_announce = true, needs_sync = true}
 	    end;
-	AccessMode == read_only, Reason /= {dumper,add_table_copy} ->
+	AccessMode == read_only, not AddTableCopy ->
 	    fun() -> disc_load_table(Tab, Reason, ReplyTo) end;
 	true ->
 	    fun() ->
diff --git a/lib/mnesia/src/mnesia_dumper.erl b/lib/mnesia/src/mnesia_dumper.erl
index e2a0aa3bda..eb02a585a6 100644
--- a/lib/mnesia/src/mnesia_dumper.erl
+++ b/lib/mnesia/src/mnesia_dumper.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -34,11 +35,15 @@
 -export([
 	 get_log_writes/0,
 	 incr_log_writes/0,
+         needs_dump_ets/1,
 	 raw_dump_table/2,
 	 raw_named_dump_table/2,
+	 dump_to_logfile/2,
+	 load_from_logfile/3,
 	 start_regulator/0,
 	 opt_dump_log/1,
-	 update/3
+	 update/3,
+	 snapshot_dcd/1
 	]).
 
  %% Internal stuff
@@ -85,7 +90,7 @@ adjust_log_writes(DoCast) ->
 	    %% Don't care if we lost a few writes
 	    mnesia_lib:set_counter(trans_log_writes_left, Max),
 	    Diff = Max - Left,
-	    mnesia_lib:incr_counter(trans_log_writes, Diff),
+	    _ = mnesia_lib:incr_counter(trans_log_writes, Diff),
 	    global:del_lock(Token, [node()])
     end.
 
@@ -99,6 +104,19 @@ opt_dump_log(InitBy) ->
 	  end,
     perform_dump(InitBy, Reg).
 
+snapshot_dcd(Tables) ->
+    lists:foreach(
+      fun(Tab) ->
+	      case mnesia_lib:storage_type_at_node(node(), Tab) of
+		  disc_copies ->
+		      mnesia_log:ets2dcd(Tab);
+		  _ ->
+		      %% Storage type was checked before queueing the op, though
+		      skip
+	      end
+      end, Tables),
+    dumped.
+
 %% Scan for decisions
 perform_dump(InitBy, Regulator) when InitBy == scan_decisions ->
     ?eval_debug_fun({?MODULE, perform_dump}, [InitBy]),
@@ -122,7 +140,7 @@ perform_dump(InitBy, Regulator) ->
 	    U = mnesia_monitor:get_env(dump_log_update_in_place),
 	    Cont = mnesia_log:init_log_dump(),
 	    mnesia_recover:sync(),
-	    case catch do_perform_dump(Cont, U, InitBy, Regulator, undefined) of
+	    try do_perform_dump(Cont, U, InitBy, Regulator, undefined) of
 		ok ->
 		    ?eval_debug_fun({?MODULE, post_dump}, [InitBy]),
 		    case mnesia_monitor:use_dir() of
@@ -133,17 +151,15 @@ perform_dump(InitBy, Regulator) ->
 		    end,
 		    mnesia_recover:allow_garb(),
 		    %% And now to the crucial point...
-		    mnesia_log:confirm_log_dump(Diff);
-		{error, Reason} ->
-		    {error, Reason};
- 		{'EXIT', {Desc, Reason}} ->
+		    mnesia_log:confirm_log_dump(Diff)
+	    catch exit:Reason when Reason =/= fatal ->
 		    case mnesia_monitor:get_env(auto_repair) of
 			true ->
-			    mnesia_lib:important(Desc, Reason),
+			    mnesia_lib:important(error, Reason),
 			    %% Ignore rest of the log
 			    mnesia_log:confirm_log_dump(Diff);
 			false ->
-			    fatal(Desc, Reason)
+			    fatal(error, Reason)
 		    end
 	    end;
 	{error, Reason} ->
@@ -161,24 +177,25 @@ scan_decisions(Fname, InitBy, Regulator) ->
 	    mnesia_log:open_log(Name, Header, Fname, Exists,
 				mnesia_monitor:get_env(auto_repair), read_only),
 	    Cont = start,
-	    Res = (catch do_perform_dump(Cont, false, InitBy, Regulator, undefined)),
-	    mnesia_log:close_log(Name),
-	    case Res of
-		ok -> ok;
-		{'EXIT', Reason} -> {error, Reason}
+	    try
+		do_perform_dump(Cont, false, InitBy, Regulator, undefined)
+	    catch exit:Reason when Reason =/= fatal ->
+		    {error, Reason}
+	    after mnesia_log:close_log(Name)
 	    end
     end.
 
 do_perform_dump(Cont, InPlace, InitBy, Regulator, OldVersion) ->
     case mnesia_log:chunk_log(Cont) of
 	{C2, Recs} ->
-	    case catch insert_recs(Recs, InPlace, InitBy, Regulator, OldVersion) of
-		{'EXIT', R} ->
-		    Reason = {"Transaction log dump error: ~p~n", [R]},
-		    close_files(InPlace, {error, Reason}, InitBy),
-		    exit(Reason);
+	    try insert_recs(Recs, InPlace, InitBy, Regulator, OldVersion) of
 		Version ->
 		    do_perform_dump(C2, InPlace, InitBy, Regulator, Version)
+	    catch _:R when R =/= fatal ->
+		    ST = erlang:get_stacktrace(),
+		    Reason = {"Transaction log dump error: ~p~n", [{R, ST}]},
+		    close_files(InPlace, {error, Reason}, InitBy),
+		    exit(Reason)
 	    end;
 	eof ->
 	    close_files(InPlace, ok, InitBy),
@@ -212,11 +229,11 @@ insert_rec(Rec, InPlace, InitBy, LogV) when is_record(Rec, commit) ->
     D = Rec#commit.decision,
     case mnesia_recover:wait_for_decision(D, InitBy) of
 	{Tid, committed} ->
-	    do_insert_rec(Tid, Rec, InPlace, InitBy, LogV);
+	    do_insert_rec(Tid, mnesia_tm:new_cr_format(Rec), InPlace, InitBy, LogV);
 	{Tid, aborted} ->
 	    case InitBy of
 		startup ->
-		    mnesia_schema:undo_prepare_commit(Tid, Rec);
+		    mnesia_schema:undo_prepare_commit(Tid, mnesia_tm:new_cr_format(Rec));
 		_ ->
 		    ok
 	    end
@@ -256,15 +273,30 @@ do_insert_rec(Tid, Rec, InPlace, InitBy, LogV) ->
 	    end
     end,
     D = Rec#commit.disc_copies,
+    ExtOps = commit_ext(Rec),
     insert_ops(Tid, disc_copies, D, InPlace, InitBy, LogV),
+    [insert_ops(Tid, Ext, Ops, InPlace, InitBy, LogV) ||
+	{Ext, Ops} <- ExtOps,
+	storage_semantics(Ext) == disc_copies],
     case InitBy of
 	startup ->
 	    DO = Rec#commit.disc_only_copies,
-	    insert_ops(Tid, disc_only_copies, DO, InPlace, InitBy, LogV);
+	    insert_ops(Tid, disc_only_copies, DO, InPlace, InitBy, LogV),
+	    [insert_ops(Tid, Ext, Ops, InPlace, InitBy, LogV) ||
+		{Ext, Ops} <- ExtOps, storage_semantics(Ext) == disc_only_copies];
 	_ ->
 	    ignore
     end.
 
+commit_ext(#commit{ext = []}) -> [];
+commit_ext(#commit{ext = Ext}) ->
+    case lists:keyfind(ext_copies, 1, Ext) of
+	{_, C} ->
+	    lists:foldl(fun({Ext0, Op}, D) ->
+				orddict:append(Ext0, Op, D)
+			end, orddict:new(), C);
+	false -> []
+    end.
 
 update(_Tid, [], _DumperMode) ->
     dumped;
@@ -288,17 +320,16 @@ perform_update(Tid, SchemaOps, _DumperMode, _UseDir) ->
 
     InitBy = fast_schema_update,
     InPlace = mnesia_monitor:get_env(dump_log_update_in_place),
-    ?eval_debug_fun({?MODULE, dump_schema_op}, [InitBy]),
-    case catch insert_ops(Tid, schema_ops, SchemaOps, InPlace, InitBy,
-			  mnesia_log:version()) of
-	{'EXIT', Reason} ->
-	    Error = {error, {"Schema update error", Reason}},
+    try insert_ops(Tid, schema_ops, SchemaOps, InPlace, InitBy,
+		   mnesia_log:version()),
+	 ?eval_debug_fun({?MODULE, post_dump}, [InitBy]),
+	 close_files(InPlace, ok, InitBy),
+	 ok
+    catch _:Reason when Reason =/= fatal ->
+	    ST = erlang:get_stacktrace(),
+	    Error = {error, {"Schema update error", {Reason, ST}}},
 	    close_files(InPlace, Error, InitBy),
-            fatal("Schema update error ~p ~p", [Reason, SchemaOps]);
-	_ ->
-	    ?eval_debug_fun({?MODULE, post_dump}, [InitBy]),
-	    close_files(InPlace, ok, InitBy),
-	    ok
+            fatal("Schema update error ~p ~p", [{Reason,ST}, SchemaOps])
     end.
 
 insert_ops(_Tid, _Storage, [], _InPlace, _InitBy, _) ->    ok;
@@ -316,14 +347,15 @@ insert_ops(Tid, Storage, [Op | Ops], InPlace, InitBy, Ver) when Ver < "4.3" ->
 %% Normal ops
 
 disc_insert(_Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy) ->
-    case open_files(Tab, Storage, InPlace, InitBy) of
+    Semantics = storage_semantics(Storage),
+    case open_files(Tab, Semantics, Storage, InPlace, InitBy) of
 	true ->
-	    case Storage of
+	    case Semantics of
 		disc_copies when Tab /= schema ->
 		    mnesia_log:append({?MODULE,Tab}, {{Tab, Key}, Val, Op}),
 		    ok;
 		_ ->
-		    dets_insert(Op,Tab,Key,Val)
+		    dets_insert(Op,Tab,Key,Val,Storage)
 	    end;
 	false ->
 	    ignore
@@ -335,36 +367,37 @@ disc_insert(_Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy) ->
 %% Otherwise we will get a double increment.
 %% This is perfect but update_counter is a dirty op.
 
-dets_insert(Op,Tab,Key,Val) ->
+dets_insert(Op,Tab,Key,Val, Storage0) ->
+    Storage = if Tab == schema -> disc_only_copies;
+		 true -> Storage0
+	      end,
     case Op of
 	write ->
 	    dets_updated(Tab,Key),
-	    ok = dets:insert(Tab, Val);
+	    ok = mnesia_lib:db_put(Storage, Tab, Val);
 	delete ->
 	    dets_updated(Tab,Key),
-	    ok = dets:delete(Tab, Key);
+	    ok = mnesia_lib:db_erase(Storage, Tab, Key);
 	update_counter ->
 	    case dets_incr_counter(Tab,Key) of
 		true ->
 		    {RecName, Incr} = Val,
-		    case catch dets:update_counter(Tab, Key, Incr) of
-			CounterVal when is_integer(CounterVal) ->
-			    ok;
-			_ when Incr < 0 ->
+		    try _ = mnesia_lib:db_update_counter(Storage, Tab, Key, Incr)
+		    catch error:_ when Incr < 0 ->
 			    Zero = {RecName, Key, 0},
-			    ok = dets:insert(Tab, Zero);
-			_ ->
+			    ok = mnesia_lib:db_put(Storage, Tab, Zero);
+			  error:_ ->
 			    Init = {RecName, Key, Incr},
-			    ok = dets:insert(Tab, Init)
+			    ok = mnesia_lib:db_put(Storage, Tab, Init)
 		    end;
 		false ->  ok
 	    end;
 	delete_object ->
 	    dets_updated(Tab,Key),
-	    ok = dets:delete_object(Tab, Val);
+	    mnesia_lib:db_match_erase(Storage, Tab, Val);
 	clear_table ->
 	    dets_cleared(Tab),
-	    ok = dets:delete_all_objects(Tab)
+	    ok = mnesia_lib:db_match_erase(Storage, Tab, '_')
     end.
 
 dets_updated(Tab,Key) ->
@@ -419,23 +452,29 @@ insert(_Tid, _Storage, _Tab, _Key, [], _Op, _InPlace, _InitBy) ->
     ok;
 
 insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy) ->
+    Semantics = storage_semantics(Storage),
     Item = {{Tab, Key}, Val, Op},
     case InitBy of
 	startup ->
 	    disc_insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy);
 
-	_ when Storage == ram_copies ->
+	_ when Semantics == ram_copies ->
 	    mnesia_tm:do_update_op(Tid, Storage, Item),
 	    Snmp = mnesia_tm:prepare_snmp(Tab, Key, [Item]),
 	    mnesia_tm:do_snmp(Tid, Snmp);
 
-	_ when Storage == disc_copies ->
+	_ when Semantics == disc_copies ->
 	    disc_insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy),
 	    mnesia_tm:do_update_op(Tid, Storage, Item),
 	    Snmp = mnesia_tm:prepare_snmp(Tab, Key, [Item]),
 	    mnesia_tm:do_snmp(Tid, Snmp);
 
-	_ when Storage == disc_only_copies ->
+	_ when Semantics == disc_only_copies ->
+	    mnesia_tm:do_update_op(Tid, Storage, Item),
+	    Snmp = mnesia_tm:prepare_snmp(Tab, Key, [Item]),
+	    mnesia_tm:do_snmp(Tid, Snmp);
+
+	_ when element(1, Storage) == ext ->
 	    mnesia_tm:do_update_op(Tid, Storage, Item),
 	    Snmp = mnesia_tm:prepare_snmp(Tab, Key, [Item]),
 	    mnesia_tm:do_snmp(Tid, Snmp);
@@ -444,6 +483,9 @@ insert(Tid, Storage, Tab, Key, Val, Op, InPlace, InitBy) ->
 	    ignore
     end.
 
+disc_delete_table(Tab, {ext, Alias, Mod}) ->
+    Mod:close_table(Alias, Tab),
+    Mod:delete_table(Alias, Tab);
 disc_delete_table(Tab, Storage) ->
     case mnesia_monitor:use_dir() of
 	true ->
@@ -451,7 +493,8 @@ disc_delete_table(Tab, Storage) ->
 		Storage == disc_only_copies; Tab == schema ->
 		    mnesia_monitor:unsafe_close_dets(Tab),
 		    Dat = mnesia_lib:tab2dat(Tab),
-		    file:delete(Dat);
+		    file:delete(Dat),
+		    ok;
 		true ->
 		    DclFile = mnesia_lib:tab2dcl(Tab),
 		    case get({?MODULE,Tab}) of
@@ -466,16 +509,20 @@ disc_delete_table(Tab, Storage) ->
 		    file:delete(DcdFile),
 		    ok
 	    end,
-	    erase({?MODULE, Tab});
+	    erase({?MODULE, Tab}),
+	    ok;
 	false ->
-	    ignore
+	    ok
     end.
 
-disc_delete_indecies(_Tab, _Cs, Storage) when Storage /= disc_only_copies ->
-    ignore;
-disc_delete_indecies(Tab, Cs, disc_only_copies) ->
-    Indecies = Cs#cstruct.index,
-    mnesia_index:del_transient(Tab, Indecies, disc_only_copies).
+disc_delete_indecies(Tab, Cs, Storage) ->
+    case storage_semantics(Storage) of
+	disc_only_copies ->
+	    Indecies = Cs#cstruct.index,
+	    mnesia_index:del_transient(Tab, Indecies, Storage);
+	_ ->
+	    ok
+    end.
 
 insert_op(Tid, Storage, {{Tab, Key}, Val, Op}, InPlace, InitBy) ->
     %% Propagate to disc only
@@ -501,6 +548,8 @@ insert_op(Tid, _, {op, change_table_copy_type, N, FromS, ToS, TabDef}, InPlace,
     Cs = mnesia_schema:list2cs(TabDef),
     Val = mnesia_schema:insert_cstruct(Tid, Cs, true), % Update ram only
     {schema, Tab, _} = Val,
+    FromSem = storage_semantics(FromS),
+    ToSem = storage_semantics(ToS),
     case lists:member(N, val({current, db_nodes})) of
 	true when InitBy /= startup  ->
 	    mnesia_controller:add_active_replica(Tab, N, Cs);
@@ -513,59 +562,118 @@ insert_op(Tid, _, {op, change_table_copy_type, N, FromS, ToS, TabDef}, InPlace,
 	    Dat  = mnesia_lib:tab2dat(Tab),
 	    Dcd  = mnesia_lib:tab2dcd(Tab),
 	    Dcl  = mnesia_lib:tab2dcl(Tab),
+	    Logtmp  = mnesia_lib:tab2logtmp(Tab),
 	    case {FromS, ToS} of
-		{ram_copies, disc_copies} when Tab == schema ->
-		    ok = ensure_rename(Dmp, Dat);
-		{ram_copies, disc_copies} ->
-		    file:delete(Dcl),
-		    ok = ensure_rename(Dmp, Dcd);
-		{disc_copies, ram_copies} when Tab == schema ->
-		    mnesia_lib:set(use_dir, false),
-		    mnesia_monitor:unsafe_close_dets(Tab),
-		    file:delete(Dat);
-		{disc_copies, ram_copies} ->
-		    file:delete(Dcl),
-		    file:delete(Dcd);
-		{ram_copies, disc_only_copies} ->
-		    ok = ensure_rename(Dmp, Dat),
-		    true = open_files(Tab, disc_only_copies, InPlace, InitBy),
-		    %% ram_delete_table must be done before init_indecies,
-		    %% it uses info which is reset in init_indecies,
-		    %% it doesn't matter, because init_indecies don't use
-		    %% the ram replica of the table when creating the disc
-		    %% index; Could be improved :)
-		    mnesia_schema:ram_delete_table(Tab, FromS),
-		    PosList = Cs#cstruct.index,
-		    mnesia_index:init_indecies(Tab, disc_only_copies, PosList);
-		{disc_only_copies, ram_copies} ->
-		    mnesia_monitor:unsafe_close_dets(Tab),
-		    disc_delete_indecies(Tab, Cs, disc_only_copies),
-		    case InitBy of
-			startup ->
-			    ignore;
+		{{ext,_FromAlias,_FromMod},{ext,ToAlias,ToMod}} ->
+		    disc_delete_table(Tab, FromS),
+                    ok = ToMod:delete_table(ToAlias, Tab),
+		    ok = mnesia_monitor:unsafe_create_external(Tab, ToAlias, ToMod, TabDef),
+		    ok = ToMod:load_table(ToAlias, Tab, {dumper,change_table_copy_type}, TabDef),
+		    ok = load_from_logfile(ToS, Tab, Logtmp),
+		    file:delete(Logtmp),
+		    restore_indexes(Tab, ToS, Cs);
+
+		{_,{ext,ToAlias,ToMod}} ->
+		    case FromSem of
+			ram_copies ->
+			    mnesia_schema:ram_delete_table(Tab, FromS);
 			_ ->
-			    mnesia_controller:get_disc_copy(Tab)
+			    if FromSem == disc_copies ->
+				    mnesia_schema:ram_delete_table(
+				      Tab, FromS);
+			       true -> ok
+			    end,
+			    disc_delete_table(Tab, FromS)
 		    end,
-		    disc_delete_table(Tab, disc_only_copies);
-		{disc_copies, disc_only_copies} ->
-		    ok = ensure_rename(Dmp, Dat),
-		    true = open_files(Tab, disc_only_copies, InPlace, InitBy),
-		    mnesia_schema:ram_delete_table(Tab, FromS),
-		    PosList = Cs#cstruct.index,
-		    mnesia_index:init_indecies(Tab, disc_only_copies, PosList),
-		    file:delete(Dcl),
-		    file:delete(Dcd);
-		{disc_only_copies, disc_copies} ->
-		    mnesia_monitor:unsafe_close_dets(Tab),
-		    disc_delete_indecies(Tab, Cs, disc_only_copies),
-		    case InitBy of
-			startup ->
-			    ignore;
-			_ ->
-			    mnesia_log:ets2dcd(Tab),
-			    mnesia_controller:get_disc_copy(Tab),
-			    disc_delete_table(Tab, disc_only_copies)
-		    end
+
+                    ok = ToMod:delete_table(ToAlias, Tab),
+		    ok = mnesia_monitor:unsafe_create_external(Tab, ToAlias, ToMod, TabDef),
+		    ok = ToMod:load_table(ToAlias, Tab, {dumper,change_table_copy_type}, TabDef),
+		    ok = load_from_logfile(ToS, Tab, Logtmp),
+		    file:delete(Logtmp),
+		    restore_indexes(Tab, ToS, Cs);
+
+		{{ext,_FromAlias,_FromMod} = FromS, ToS} ->
+		    disc_delete_table(Tab, FromS),
+		    case ToS of
+			ram_copies ->
+			    change_disc_to_ram(
+			      Tab, Cs, FromS, ToS, Logtmp, InitBy);
+			disc_copies ->
+			    Args = [{keypos, 2}, public, named_table,
+				    Cs#cstruct.type],
+			    mnesia_monitor:mktab(Tab, Args),
+			    ok = load_from_logfile(ToS, Tab, Logtmp),
+			    file:delete(Logtmp);
+			disc_only_copies ->
+			    %% ok = ensure_rename(Dmp, Dat),
+			    true = open_files(Tab, ToS, InPlace, InitBy),
+			    ok = load_from_logfile(ToS, Tab, Logtmp),
+			    file:delete(Logtmp)
+		    end,
+		    restore_indexes(Tab, ToS, Cs);
+
+		_NoneAreExt ->
+
+                    case {FromSem, ToSem} of
+                        {ram_copies, disc_copies} when Tab == schema ->
+                            ok = ensure_rename(Dmp, Dat);
+                        {ram_copies, disc_copies} ->
+                            file:delete(Dcl),
+                            ok = ensure_rename(Dmp, Dcd);
+                        {disc_copies, ram_copies} when Tab == schema ->
+                            mnesia_lib:set(use_dir, false),
+                            mnesia_monitor:unsafe_close_dets(Tab),
+                            ok = file:delete(Dat);
+                        {disc_copies, ram_copies} ->
+                            _ = file:delete(Dcl),
+                            _ = file:delete(Dcd),
+                            ok;
+                        {ram_copies, disc_only_copies} ->
+                            ok = ensure_rename(Dmp, Dat),
+                            true = open_files(Tab, ToS, InPlace, InitBy),
+                            %% ram_delete_table must be done before
+                            %% init_indecies, it uses info which is reset
+                            %% in init_indecies, it doesn't matter, because
+                            %% init_indecies don't use the ram replica of
+                            %% the table when creating the disc index;
+                            %% Could be improved :)
+                            mnesia_schema:ram_delete_table(Tab, FromS),
+			    restore_indexes(Tab, ToS, Cs);
+                        {disc_only_copies, ram_copies} when FromS == disc_only_copies ->
+                            mnesia_monitor:unsafe_close_dets(Tab),
+                            disc_delete_indecies(Tab, Cs, FromS),
+                            case InitBy of
+                                startup ->
+                                    ignore;
+                                _ ->
+                                    mnesia_controller:get_disc_copy(Tab),
+                                    ok
+                            end,
+                            disc_delete_table(Tab, FromS);
+                        {disc_only_copies, ram_copies} when element(1, FromS) == ext ->
+			    change_disc_to_ram(
+			      Tab, Cs, FromS, ToS, Logtmp, InitBy);
+                        {disc_copies, disc_only_copies} ->
+                            ok = ensure_rename(Dmp, Dat),
+                            true = open_files(Tab, ToS, InPlace, InitBy),
+                            mnesia_schema:ram_delete_table(Tab, FromS),
+			    restore_indexes(Tab, ToS, Cs),
+			    _ = file:delete(Dcl),
+                            _ = file:delete(Dcd),
+                            ok;
+                        {disc_only_copies, disc_copies} ->
+                            mnesia_monitor:unsafe_close_dets(Tab),
+                            disc_delete_indecies(Tab, Cs, disc_only_copies),
+                            case InitBy of
+                                startup ->
+                                    ignore;
+                                _ ->
+                                    mnesia_log:ets2dcd(Tab),
+                                    mnesia_controller:get_disc_copy(Tab),
+                                    disc_delete_table(Tab, disc_only_copies)
+                            end
+                    end
 	    end;
 	true ->
 	    ignore
@@ -590,6 +698,9 @@ insert_op(Tid, _, {op, restore_recreate, TabDef}, InPlace, InitBy) ->
     Tab = Cs#cstruct.name,
     Type = Cs#cstruct.type,
     Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
+    Semantics = if Storage==unknown -> unknown;
+		   true -> storage_semantics(Storage)
+		end,
     %% Delete all possibly existing files and tables
     disc_delete_table(Tab, Storage),
     disc_delete_indecies(Tab, Cs, Storage),
@@ -608,13 +719,13 @@ insert_op(Tid, _, {op, restore_recreate, TabDef}, InPlace, InitBy) ->
     
     %% And create new ones..
     if
-	(InitBy == startup) or (Storage == unknown) ->
+	(InitBy == startup) or (Semantics == unknown) ->
 	    ignore;
-	Storage == ram_copies ->
+	Semantics == ram_copies ->
 	    EtsProps = proplists:get_value(ets, StorageProps, []),
 	    Args = [{keypos, 2}, public, named_table, Type | EtsProps],
 	    mnesia_monitor:mktab(Tab, Args);
-	Storage == disc_copies ->
+	Semantics == disc_copies ->
 	    EtsProps = proplists:get_value(ets, StorageProps, []),
 	    Args = [{keypos, 2}, public, named_table, Type | EtsProps],
 	    mnesia_monitor:mktab(Tab, Args),
@@ -623,7 +734,7 @@ insert_op(Tid, _, {op, restore_recreate, TabDef}, InPlace, InitBy) ->
 		    {repair, false}, {mode, read_write}],
 	    {ok, Log} = mnesia_monitor:open_log(FArg),
 	    mnesia_monitor:unsafe_close_log(Log);
-	Storage == disc_only_copies ->
+	Storage == disc_only_copies ->  % note: Storage, not Semantics
 	    File = mnesia_lib:tab2dat(Tab),
 	    file:delete(File),
 	    DetsProps = proplists:get_value(dets, StorageProps, []),
@@ -632,7 +743,10 @@ insert_op(Tid, _, {op, restore_recreate, TabDef}, InPlace, InitBy) ->
 		    {keypos, 2},
 		    {repair, mnesia_monitor:get_env(auto_repair)} 
 		    | DetsProps ],
-	    mnesia_monitor:open_dets(Tab, Args)
+	    mnesia_monitor:open_dets(Tab, Args);
+	element(1,Storage) == ext ->
+	    {ext, Alias, Mod} = Storage,
+	    Mod:create_table(Alias, Tab, [])
     end,
     insert_op(Tid, ignore, {op, create_table, TabDef}, InPlace, InitBy);
 
@@ -642,9 +756,10 @@ insert_op(Tid, _, {op, create_table, TabDef}, InPlace, InitBy) ->
     Tab = Cs#cstruct.name,
     Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
     StorageProps = Cs#cstruct.storage_properties,
+    Semantics = storage_semantics(Storage),
     case InitBy of
 	startup ->
-	    case Storage of
+	    case Semantics of
 		unknown ->
 		    ignore;
 		ram_copies ->
@@ -662,20 +777,10 @@ insert_op(Tid, _, {op, create_table, TabDef}, InPlace, InitBy) ->
 						read_write),
 			    mnesia_log:unsafe_close_log(temp)
 		    end;
-		_ ->
+		disc_only_copies ->
 		    DetsProps = proplists:get_value(dets, StorageProps, []),
 
-		    Args = [{file, mnesia_lib:tab2dat(Tab)},
-			    {type, mnesia_lib:disk_type(Tab, Cs#cstruct.type)},
-			    {keypos, 2},
-			    {repair, mnesia_monitor:get_env(auto_repair)} 
-			    | DetsProps ],
-		    case mnesia_monitor:open_dets(Tab, Args) of
-			{ok, _} ->
-			    mnesia_monitor:unsafe_close_dets(Tab);
-			{error, Error} ->
-			    exit({"Failed to create dets table", Error})
-		    end
+		    try_create_disc_only_copy(Storage, Tab, Cs, DetsProps)
 	    end;
 	_ ->
 	    Copies = mnesia_lib:copy_holders(Cs),
@@ -698,7 +803,7 @@ insert_op(Tid, _, {op, create_table, TabDef}, InPlace, InitBy) ->
 			false ->
 			    mnesia_lib:set({Tab, where_to_read}, node())
 		    end,
-		    case Storage of
+		    case Semantics of
 			ram_copies ->
 			    ignore;
 			_ ->
@@ -766,7 +871,7 @@ insert_op(Tid, _, {op, clear_table, TabDef}, InPlace, InitBy) ->
 	    end,
 	    %% Need to catch this, it crashes on ram_copies if
 	    %% the op comes before table is loaded at startup.
-	    catch insert(Tid, Storage, Tab, '_', Oid, clear_table, InPlace, InitBy)
+	    ?CATCH(insert(Tid, Storage, Tab, '_', Oid, clear_table, InPlace, InitBy))
     end;
 
 insert_op(Tid, _, {op, merge_schema, TabDef}, InPlace, InitBy) ->
@@ -821,7 +926,7 @@ insert_op(Tid, _, {op, del_table_copy, Storage, Node, TabDef}, InPlace, InitBy)
 	    insert_cstruct(Tid, Cs, true, InPlace, InitBy);
         Tab /= schema ->
 	    mnesia_controller:del_active_replica(Tab, Node),
-	    mnesia_lib:del({Tab, Storage}, Node),
+	    mnesia_lib:del({Tab, storage_alias(Storage)}, Node),
 	    if
 		Node == node() ->
 		    case Cs#cstruct.local_content of
@@ -879,9 +984,10 @@ insert_op(Tid, _, {op, add_index, Pos, TabDef}, InPlace, InitBy) ->
     Cs = mnesia_schema:list2cs(TabDef),
     Tab = insert_cstruct(Tid, Cs, true, InPlace, InitBy),
     Storage = mnesia_lib:cs_to_storage_type(node(), Cs),
+    Semantics = storage_semantics(Storage),
     case InitBy of
-	startup when Storage == disc_only_copies ->
-	    true = open_files(Tab, Storage, InPlace, InitBy),
+	startup when Semantics == disc_only_copies ->
+	    true = open_files(Tab, Semantics, Storage, InPlace, InitBy),
 	    mnesia_index:init_indecies(Tab, Storage, [Pos]);
 	startup ->
 	    ignore;
@@ -902,6 +1008,8 @@ insert_op(Tid, _, {op, del_index, Pos, TabDef}, InPlace, InitBy) ->
 	    mnesia_index:del_index_table(Tab, Storage, Pos);
 	startup ->
 	    ignore;
+        _ when element(1, Storage) == ext ->
+	    mnesia_index:del_index_table(Tab, Storage, Pos);
 	_ ->
 	    mnesia_index:del_index_table(Tab, Storage, Pos)
     end,
@@ -941,19 +1049,68 @@ insert_op(Tid, _, {op, change_table_frag, _Change, TabDef}, InPlace, InitBy) ->
     Cs = mnesia_schema:list2cs(TabDef),
     insert_cstruct(Tid, Cs, true, InPlace, InitBy).
 
-open_files(Tab, Storage, UpdateInPlace, InitBy)
-  when Storage /= unknown, Storage /= ram_copies ->
+
+storage_semantics({ext, Alias, Mod}) ->
+    Mod:semantics(Alias, storage);
+storage_semantics(Storage) when is_atom(Storage) ->
+    Storage.
+
+storage_alias({ext, Alias, _}) ->
+    Alias;
+storage_alias(Storage) when is_atom(Storage) ->
+    Storage.
+
+change_disc_to_ram(Tab, Cs, FromS, ToS, Logtmp, InitBy) ->
+    disc_delete_indecies(Tab, Cs, FromS),
+    case InitBy of
+	startup ->
+	    ignore;
+	_ ->
+	    %% ram table will already have been created
+	    Tab = ets:info(Tab, name),  %% assertion
+	    load_from_logfile(ToS, Tab, Logtmp),
+	    PosList = Cs#cstruct.index,
+	    mnesia_index:init_indecies(Tab, ToS, PosList)
+    end,
+    disc_delete_table(Tab, FromS).
+
+
+try_create_disc_only_copy({ext,Alias,Mod}, Tab, Cs, _) ->
+    Mod:create_table(Alias, Tab, mnesia_schema:cs2list(Cs));
+try_create_disc_only_copy(disc_only_copies, Tab, Cs, DetsProps) ->
+    Args = [{file, mnesia_lib:tab2dat(Tab)},
+	    {type, mnesia_lib:disk_type(Tab, Cs#cstruct.type)},
+	    {keypos, 2},
+	    {repair, mnesia_monitor:get_env(auto_repair)}
+	    | DetsProps],
+    case mnesia_monitor:open_dets(Tab, Args) of
+	{ok, _} ->
+	    mnesia_monitor:unsafe_close_dets(Tab);
+	{error, Error} ->
+	    exit({"Failed to create dets table", Error})
+    end.
+
+restore_indexes(Tab, ToS, Cs) ->
+    PosList = Cs#cstruct.index,
+    mnesia_index:init_indecies(Tab, ToS, PosList).
+
+
+open_files(Tab, Storage, UpdateInPlace, InitBy) ->
+    open_files(Tab, storage_semantics(Storage), Storage, UpdateInPlace, InitBy).
+
+open_files(Tab, Semantics, Storage, UpdateInPlace, InitBy)
+  when Storage /= unknown, Semantics /= ram_copies ->
     case get({?MODULE, Tab}) of
 	undefined ->
 	    case ?catch_val({Tab, setorbag}) of
 		{'EXIT', _} ->
 		    false;
 		Type ->
-		    case Storage of
-			disc_copies when Tab /= schema ->
+		    Cs = val({Tab, cstruct}),
+		    if Semantics  == disc_copies, Tab /= schema ->
 			    Bool = open_disc_copies(Tab, InitBy),
 			    Bool;
-			_ ->
+		       Storage == disc_only_copies; Tab == schema ->
 			    Props = val({Tab, storage_properties}),
 			    DetsProps = proplists:get_value(dets, Props, []),
 			    Fname = prepare_open(Tab, UpdateInPlace),
@@ -964,6 +1121,12 @@ open_files(Tab, Storage, UpdateInPlace, InitBy)
 				    | DetsProps],
 			    {ok, _} = mnesia_monitor:open_dets(Tab, Args),
 			    put({?MODULE, Tab}, {opened_dumper, dat}),
+			    true;
+		       element(1, Storage) == ext ->
+			    {ext, Alias, Mod} = Storage,
+			    Mod:load_table(Alias, Tab, InitBy,
+					   mnesia_schema:cs2list(Cs)),
+			    put({?MODULE, Tab}, {opened_dumper, ext}),
 			    true
 		    end
 	    end;
@@ -972,32 +1135,14 @@ open_files(Tab, Storage, UpdateInPlace, InitBy)
 	{opened_dumper, _} ->
 	    true
     end;
-open_files(_Tab, _Storage, _UpdateInPlace, _InitBy) ->
+open_files(_Tab, _Semantics, _Storage, _UpdateInPlace, _InitBy) ->
     false.
 
 open_disc_copies(Tab, InitBy) ->
-    DclF = mnesia_lib:tab2dcl(Tab),
-    DumpEts =
-	case file:read_file_info(DclF) of
-	    {error, enoent} ->
-		false;
-	    {ok, DclInfo} ->
-		DcdF =  mnesia_lib:tab2dcd(Tab),
-		case file:read_file_info(DcdF) of
-		    {error, Reason} ->
-			mnesia_lib:dbg_out("File ~p info_error ~p ~n",
-					   [DcdF, Reason]),
-			true;
-		    {ok, DcdInfo} ->
-			Mul = case ?catch_val(dc_dump_limit) of
-				  {'EXIT', _} -> ?DumpToEtsMultiplier;
-				  Val -> Val
-			      end,
-			DcdInfo#file_info.size =< (DclInfo#file_info.size * Mul)
-		end
-	end,
+    DumpEts = needs_dump_ets(Tab),
     if
 	DumpEts == false; InitBy == startup ->
+            DclF = mnesia_lib:tab2dcl(Tab),
 	    mnesia_log:open_log({?MODULE,Tab},
 				mnesia_log:dcl_log_header(),
 				DclF,
@@ -1012,6 +1157,27 @@ open_disc_copies(Tab, InitBy) ->
 	    false
     end.
 
+needs_dump_ets(Tab) ->
+    DclF = mnesia_lib:tab2dcl(Tab),
+    case file:read_file_info(DclF) of
+        {error, enoent} ->
+            false;
+        {ok, DclInfo} ->
+            DcdF =  mnesia_lib:tab2dcd(Tab),
+            case file:read_file_info(DcdF) of
+                {error, Reason} ->
+                    mnesia_lib:dbg_out("File ~p info_error ~p ~n",
+                                       [DcdF, Reason]),
+                    true;
+                {ok, DcdInfo} ->
+                    Mul = case ?catch_val(dc_dump_limit) of
+                              {'EXIT', _} -> ?DumpToEtsMultiplier;
+                              Val -> Val
+                          end,
+                    DcdInfo#file_info.size =< (DclInfo#file_info.size * Mul)
+            end
+    end.
+
 %% Always opens the dcl file for writing overriding already_dumped
 %% mechanismen, used for schema transactions.
 open_dcl(Tab) ->
@@ -1037,14 +1203,13 @@ prepare_open(Tab, UpdateInPlace) ->
 	    Dat;
 	false ->
 	    Tmp = mnesia_lib:tab2tmp(Tab),
-	    case catch mnesia_lib:copy_file(Dat, Tmp) of
-		ok ->
-		    Tmp;
-		Error ->
+	    try ok = mnesia_lib:copy_file(Dat, Tmp)
+	    catch error:Error ->
 		    fatal("Cannot copy dets file ~p to ~p: ~p~n",
 			  [Dat, Tmp, Error])
-	    end
-	end.
+	    end,
+	    Tmp
+    end.
 
 del_opened_tab(Tab) ->
     erase({?MODULE, Tab}).
@@ -1057,12 +1222,13 @@ close_files(InPlace, Outcome, InitBy, [{{?MODULE, Tab}, already_dumped} | Tail])
     close_files(InPlace, Outcome, InitBy, Tail);
 close_files(InPlace, Outcome, InitBy, [{{?MODULE, Tab}, {opened_dumper, Type}} | Tail]) ->
     erase({?MODULE, Tab}),
-    case val({Tab, storage_type}) of
+    Storage = val({Tab, storage_type}),
+    case storage_semantics(Storage) of
 	disc_only_copies when InitBy /= startup ->
 	    ignore;
-	disc_copies when Tab /= schema ->
+	disc_copies when Storage /= unknown, Tab /= schema ->
 	    mnesia_log:close_log({?MODULE,Tab});
-	Storage ->
+	_ ->
 	    do_close(InPlace, Outcome, Tab, Type, Storage)
     end,
     close_files(InPlace, Outcome, InitBy, Tail);
@@ -1074,11 +1240,16 @@ close_files(_, _, _InitBy, []) ->
 
 %% If storage is unknown during close clean up files, this can happen if timing
 %% is right and dirty_write conflicts with schema operations.
+do_close(_, _, Tab, ext, {ext,Alias,Mod}) ->
+    Mod:close_table(Alias, Tab);
 do_close(_, _, Tab, dcl, unknown) ->
     mnesia_log:close_log({?MODULE,Tab}),
     file:delete(mnesia_lib:tab2dcl(Tab));
 do_close(_, _, Tab, dcl, _) ->  %% To be safe, can it happen?
     mnesia_log:close_log({?MODULE,Tab});
+do_close(_, _, _Tab, ext, unknown) ->
+    %% Not sure what to do here, but let's not crash
+    ok;
 
 do_close(InPlace, Outcome, Tab, dat, Storage) ->
     mnesia_monitor:close_dets(Tab),
@@ -1129,7 +1300,8 @@ temp_set_master_nodes() ->
     Tabs = val({schema, local_tables}),
     Masters = [{Tab, (val({Tab, disc_copies}) ++
 		      val({Tab, ram_copies}) ++
-		      val({Tab, disc_only_copies})) -- [node()]}
+		      val({Tab, disc_only_copies}) ++
+		      external_copies(Tab)) -- [node()]}
 	       || Tab <- Tabs],
     %% UseDir = false since we don't want to remember these
     %% masternodes and we are running (really soon anyway) since we want this
@@ -1137,6 +1309,13 @@ temp_set_master_nodes() ->
     mnesia_recover:log_master_nodes(Masters, false, yes),
     ok.
 
+external_copies(Tab) ->
+    case ?catch_val({Tab, external_copies}) of
+	{'EXIT',_} -> [];
+	Ext ->
+	    lists:concat([Ns || {_, Ns} <- Ext])
+    end.
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Raw dump of table. Dumper must have unique access to the ets table.
 
@@ -1166,18 +1345,16 @@ raw_named_dump_table(Tab, Ftype) ->
 		    Storage = ram_copies,
 		    mnesia_lib:db_fixtable(Storage, Tab, true),
 
-		    case catch raw_dump_table(TabRef, Tab) of
-			{'EXIT', Reason} ->
-			    mnesia_lib:db_fixtable(Storage, Tab, false),
-			    mnesia_lib:dets_sync_close(Tab),
-			    file:delete(TmpFname),
-			    mnesia_lib:unlock_table(Tab),
-			    exit({"Dump of table to disc failed", Reason});
-			ok ->
-			    mnesia_lib:db_fixtable(Storage, Tab, false),
-			    mnesia_lib:dets_sync_close(Tab),
-			    mnesia_lib:unlock_table(Tab),
-			    ok = file:rename(TmpFname, Fname)
+		    try
+			ok = raw_dump_table(TabRef, Tab),
+			ok = file:rename(TmpFname, Fname)
+		    catch _:Reason ->
+			    ?SAFE(file:delete(TmpFname)),
+			    exit({"Dump of table to disc failed", Reason})
+		    after
+			mnesia_lib:db_fixtable(Storage, Tab, false),
+			mnesia_lib:dets_sync_close(Tab),
+			mnesia_lib:unlock_table(Tab)
 		    end;
 		{error, Reason} ->
 		    mnesia_lib:unlock_table(Tab),
@@ -1190,6 +1367,59 @@ raw_named_dump_table(Tab, Ftype) ->
 raw_dump_table(DetsRef, EtsRef) ->
     dets:from_ets(DetsRef, EtsRef).
 
+dump_to_logfile(Storage, Tab) ->
+    case mnesia_monitor:use_dir() of
+	true ->
+	    Logtmp = mnesia_lib:tab2logtmp(Tab),
+	    file:delete(Logtmp),
+	    case disk_log:open([{name, make_ref()},
+				{file, Logtmp},
+				{repair, false},
+				{linkto, self()}]) of
+		{ok, Fd} ->
+		    mnesia_lib:db_fixtable(Storage, Tab, true),
+		    try do_dump_to_logfile(Storage, Tab, Fd)
+		    after
+			mnesia_lib:db_fixtable(Storage, Tab, false)
+		    end;
+		{error, _} = Error ->
+		    Error
+	    end;
+	false ->
+	    {error, {has_no_disc, node()}}
+    end.
+
+do_dump_to_logfile(Storage, Tab, Fd) ->
+    Pat = [{'_',[],['$_']}],
+    log_terms(mnesia_lib:db_select_init(Storage, Tab, Pat, 100), Storage, Tab, Pat, Fd).
+
+log_terms({Objs, Cont}, Storage, Tab, Pat, Fd) ->
+    ok = disk_log:alog_terms(Fd, Objs),
+    log_terms(mnesia_lib:db_select_cont(Storage, Cont, '_'), Storage, Tab, Pat, Fd);
+log_terms('$end_of_table', _, _, _, Fd) ->
+    disk_log:close(Fd).
+
+load_from_logfile(Storage, Tab, F) ->
+    case disk_log:open([{name, make_ref()},
+			{file, F},
+			{repair, true},
+			{linkto, self()}]) of
+	{ok, Fd} ->
+	    chunk_from_log(disk_log:chunk(Fd, start), Fd, Storage, Tab);
+	{repaired, Fd, _, _} ->
+	    chunk_from_log(disk_log:chunk(Fd, start), Fd, Storage, Tab);
+	{error, _} = E ->
+	    E
+    end.
+
+chunk_from_log({Cont, Terms}, Fd, Storage, Tab) ->
+    _ = [mnesia_lib:db_put(Storage, Tab, T) || T <- Terms],
+    chunk_from_log(disk_log:chunk(Fd, Cont), Fd, Storage, Tab);
+chunk_from_log(eof, _, _, _) ->
+    ok.
+
+
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Load regulator
 %%
@@ -1243,6 +1473,6 @@ regulate(RegulatorPid) ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason);
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
 	Value -> Value
     end.
diff --git a/lib/mnesia/src/mnesia_event.erl b/lib/mnesia/src/mnesia_event.erl
index 35fe2d4035..7320d381ea 100644
--- a/lib/mnesia/src/mnesia_event.erl
+++ b/lib/mnesia/src/mnesia_event.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -63,7 +64,7 @@ handle_event(Event, State) ->
 %%-----------------------------------------------------------------
 
 handle_info(Msg, State) ->
-    handle_any_event(Msg, State),
+    {ok, _} = handle_any_event(Msg, State),
     {ok, State}.
 
 %%-----------------------------------------------------------------
@@ -235,8 +236,7 @@ report_fatal(Format, Args, BinaryCore, CoreDumped) ->
     end.
 
 core_file(CoreDir,BinaryCore,Format,Args) ->
-    %% Integers = tuple_to_list(date()) ++ tuple_to_list(time()),
-    Integers = tuple_to_list(now()),
+    Integers = tuple_to_list(erlang:timestamp()),
     Fun = fun(I) when I < 10 -> ["_0",I];
 	     (I) -> ["_",I]
 	  end,
diff --git a/lib/mnesia/src/mnesia_ext_sup.erl b/lib/mnesia/src/mnesia_ext_sup.erl
new file mode 100644
index 0000000000..3e6c72161c
--- /dev/null
+++ b/lib/mnesia/src/mnesia_ext_sup.erl
@@ -0,0 +1,59 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1996-2015. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+%%
+%% This module implements a supervisor for external (plug-in) processes
+
+-module(mnesia_ext_sup).
+-behaviour(supervisor).
+
+-export([start/0,
+	 init/1,
+	 start_proc/4, start_proc/5,
+	 stop_proc/1]).
+
+-define(SHUTDOWN, 120000).  % 2 minutes
+
+start() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+start_proc(Name, M, F, A) ->
+    start_proc(Name, M, F, A, []).
+
+start_proc(Name, M, F, A, Opts) ->
+    [Restart, Shutdown, Type, Modules] =
+	[proplists:get_value(K, Opts, Default)
+	 || {K, Default} <- [{restart, transient},
+			     {shutdown, ?SHUTDOWN},
+			     {type, worker},
+			     {modules, [M]}]],
+    case supervisor:start_child(
+	   ?MODULE, {Name, {M,F,A}, Restart, Shutdown, Type, Modules}) of
+	{error, already_present} ->
+	    supervisor:restart_child(?MODULE, Name);
+	Other ->
+	    Other
+    end.
+
+stop_proc(Name) ->
+    supervisor:terminate_child(?MODULE, Name).
+
+init(_) ->
+    {ok, {{one_for_all, 10, 60}, []}}.
diff --git a/lib/mnesia/src/mnesia_frag.erl b/lib/mnesia/src/mnesia_frag.erl
index 4a1616e054..c6e812b36d 100644
--- a/lib/mnesia/src/mnesia_frag.erl
+++ b/lib/mnesia/src/mnesia_frag.erl
@@ -1,18 +1,19 @@
 %%%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1998-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -182,6 +183,8 @@ table_info2(ActivityId, Opaque, Tab, Frag, Item) ->
 	    length(val({Tab, disc_copies}));
 	n_disc_only_copies ->
 	    length(val({Tab, disc_only_copies}));
+	n_external_copies ->
+	    length(val({Tab, external_copies}));
 
 	frag_names ->
 	    frag_names(Tab);
@@ -406,10 +409,11 @@ verify_numbers(FH,MatchSpec) ->
     VerifyFun = fun(F) when is_integer(F), F >= 1, F =< N -> false;
 		   (_F) -> true
 		end,
-    case catch lists:filter(VerifyFun, FragNumbers) of
-	[] ->
-	    FragNumbers;
-	BadFrags ->
+    try
+	Frags = lists:filter(VerifyFun, FragNumbers),
+	Frags == [] orelse error(Frags),
+	FragNumbers
+    catch error:BadFrags ->
 	    mnesia:abort({"match_spec_to_frag_numbers: Fragment numbers out of range",
 			  BadFrags, {range, 1, N}})
     end.
@@ -437,7 +441,7 @@ remote_select(ReplyTo, Ref, NameNodes, MatchSpec) ->
 do_remote_select(ReplyTo, Ref, [{Name, Node} | NameNodes], MatchSpec) ->
     if
 	Node == node() ->
-	    Res = (catch {ok, mnesia:dirty_select(Name, MatchSpec)}),
+	    Res = ?CATCH({ok, mnesia:dirty_select(Name, MatchSpec)}),
 	    ReplyTo ! {remote_select, Ref, Node, Res},
 	    do_remote_select(ReplyTo, Ref, NameNodes, MatchSpec);
 	true ->
@@ -496,13 +500,13 @@ expand_cstruct(Cs, Mode) ->
     %% Verify keys
     ValidKeys = [foreign_key, n_fragments, node_pool,
 		 n_ram_copies, n_disc_copies, n_disc_only_copies,
-		 hash_module, hash_state],
+                 n_external_copies, hash_module, hash_state],
     Keys = mnesia_schema:check_keys(Tab, Props, ValidKeys),
     mnesia_schema:check_duplicates(Tab, Keys),
 
     %% Pick fragmentation props
     ForeignKey = mnesia_schema:pick(Tab, foreign_key, Props, undefined),
-    {ForeignKey2, N, Pool, DefaultNR, DefaultND, DefaultNDO} =
+    {ForeignKey2, N, Pool, DefaultNR, DefaultND, DefaultNDO, DefaultNExt} =
 	pick_props(Tab, Cs, ForeignKey),
 
     %% Verify node_pool
@@ -516,6 +520,7 @@ expand_cstruct(Cs, Mode) ->
     NR  = mnesia_schema:pick(Tab, n_ram_copies, Props, 0),
     ND  = mnesia_schema:pick(Tab, n_disc_copies, Props, 0),
     NDO = mnesia_schema:pick(Tab, n_disc_only_copies, Props, 0),
+    NExt = mnesia_schema:pick(Tab, n_external_copies, Props, 0),
     
     PosInt = fun(I) when is_integer(I), I >= 0 -> true;
 		(_I) -> false
@@ -526,6 +531,8 @@ expand_cstruct(Cs, Mode) ->
 			 {bad_type, Tab, {n_disc_copies, ND}}),
     mnesia_schema:verify(true, PosInt(NDO),
 			 {bad_type, Tab, {n_disc_only_copies, NDO}}),
+    mnesia_schema:verify(true, PosInt(NExt),
+			 {bad_type, Tab, {n_external_copies, NDO}}),
     
     %% Verify n_fragments
     Cs2 = verify_n_fragments(N, Cs, Mode),
@@ -540,13 +547,13 @@ expand_cstruct(Cs, Mode) ->
 		     hash_module = HashMod,
 		     hash_state  = HashState2},
     if
-	NR == 0, ND == 0, NDO == 0 ->
-	    do_expand_cstruct(Cs2, FH, N, Pool, DefaultNR, DefaultND, DefaultNDO, Mode);
+	NR == 0, ND == 0, NDO == 0, NExt == 0 ->
+	    do_expand_cstruct(Cs2, FH, N, Pool, DefaultNR, DefaultND, DefaultNDO, DefaultNExt, Mode);
 	true ->
-	    do_expand_cstruct(Cs2, FH, N, Pool, NR, ND, NDO, Mode)
+	    do_expand_cstruct(Cs2, FH, N, Pool, NR, ND, NDO, NExt, Mode)
     end.
 	    
-do_expand_cstruct(Cs, FH, N, Pool, NR, ND, NDO, Mode) ->
+do_expand_cstruct(Cs, FH, N, Pool, NR, ND, NDO, NExt, Mode) ->
     Tab = Cs#cstruct.name,
     
     LC = Cs#cstruct.local_content,
@@ -560,14 +567,15 @@ do_expand_cstruct(Cs, FH, N, Pool, NR, ND, NDO, Mode) ->
     %% Add empty fragments
     CommonProps = [{base_table, Tab}],
     Cs2 = Cs#cstruct{frag_properties = lists:sort(CommonProps)},
-    expand_frag_cstructs(N, NR, ND, NDO, Cs2, Pool, Pool, FH, Mode).
+    expand_frag_cstructs(N, NR, ND, NDO, NExt, Cs2, Pool, Pool, FH, Mode).
 
 verify_n_fragments(N, Cs, Mode) when is_integer(N), N >= 1 ->
     case Mode of
 	create ->
 	    Cs#cstruct{ram_copies = [],
 		       disc_copies = [],
-		       disc_only_copies = []};
+		       disc_only_copies = [],
+		       external_copies = []};
 	activate  ->
 	    Reason = {combine_error, Cs#cstruct.name, {n_fragments, N}},
 	    mnesia_schema:verify(1, N, Reason),
@@ -605,7 +613,8 @@ pick_props(Tab, Cs, {ForeignTab, Attr}) ->
     DefaultNR = length(val({ForeignTab, ram_copies})), 
     DefaultND = length(val({ForeignTab, disc_copies})), 
     DefaultNDO = length(val({ForeignTab, disc_only_copies})),
-    {Key, N, Pool, DefaultNR, DefaultND, DefaultNDO};
+    DefaultNExt = length(val({ForeignTab, external_copies})),
+    {Key, N, Pool, DefaultNR, DefaultND, DefaultNDO, DefaultNExt};
 pick_props(Tab, Cs, undefined) ->
     Props = Cs#cstruct.frag_properties,
     DefaultN = 1,
@@ -615,22 +624,23 @@ pick_props(Tab, Cs, undefined) ->
     DefaultNR = 1,
     DefaultND = 0,
     DefaultNDO = 0,
-    {undefined, N, Pool, DefaultNR, DefaultND, DefaultNDO};
+    DefaultNExt = 0,
+    {undefined, N, Pool, DefaultNR, DefaultND, DefaultNDO, DefaultNExt};
 pick_props(Tab, _Cs, BadKey) ->
     mnesia:abort({bad_type, Tab, {foreign_key, BadKey}}).
 
-expand_frag_cstructs(N, NR, ND, NDO, CommonCs, Dist, Pool, FH, Mode)
+expand_frag_cstructs(N, NR, ND, NDO, NExt, CommonCs, Dist, Pool, FH, Mode)
   when N > 1, Mode == create ->
     Frag = n_to_frag_name(CommonCs#cstruct.name, N),
     Cs = CommonCs#cstruct{name = Frag},
-    {Cs2, RevModDist, RestDist} = set_frag_nodes(NR, ND, NDO, Cs, Dist, []),
+    {Cs2, RevModDist, RestDist} = set_frag_nodes(NR, ND, NDO, NExt, Cs, Dist, []),
     ModDist = lists:reverse(RevModDist),
     Dist2 = rearrange_dist(Cs, ModDist, RestDist, Pool),
     %% Adjusts backwards, but it doesn't matter.
     {FH2, _FromFrags, _AdditionalWriteFrags} = adjust_before_split(FH), 
-    CsList = expand_frag_cstructs(N - 1, NR, ND, NDO, CommonCs, Dist2, Pool, FH2, Mode),
+    CsList = expand_frag_cstructs(N - 1, NR, ND, NDO, NExt, CommonCs, Dist2, Pool, FH2, Mode),
     [Cs2 | CsList];
-expand_frag_cstructs(1, NR, ND, NDO, CommonCs, Dist, Pool, FH, Mode) ->
+expand_frag_cstructs(1, NR, ND, NDO, NExt, CommonCs, Dist, Pool, FH, Mode) ->
     BaseProps = CommonCs#cstruct.frag_properties ++  
 	[{foreign_key, FH#frag_state.foreign_key},
 	 {hash_module, FH#frag_state.hash_module},
@@ -643,25 +653,29 @@ expand_frag_cstructs(1, NR, ND, NDO, CommonCs, Dist, Pool, FH, Mode) ->
 	activate ->
 	    [BaseCs];
 	create ->
-	    {BaseCs2, _, _} = set_frag_nodes(NR, ND, NDO, BaseCs, Dist, []),
+	    {BaseCs2, _, _} = set_frag_nodes(NR, ND, NDO, NExt, BaseCs, Dist, []),
 	    [BaseCs2]
     end.
     
-set_frag_nodes(NR, ND, NDO, Cs, [Head | Tail], Acc) when NR > 0 ->
+set_frag_nodes(NR, ND, NDO, NExt, Cs, [Head | Tail], Acc) when NR > 0 ->
     Pos = #cstruct.ram_copies,
     {Cs2, Head2} = set_frag_node(Cs, Pos, Head),
-    set_frag_nodes(NR - 1, ND, NDO, Cs2, Tail, [Head2 | Acc]); 
-set_frag_nodes(NR, ND, NDO, Cs, [Head | Tail], Acc) when ND > 0 ->
+    set_frag_nodes(NR - 1, ND, NDO, NExt, Cs2, Tail, [Head2 | Acc]);
+set_frag_nodes(NR, ND, NDO, NExt, Cs, [Head | Tail], Acc) when ND > 0 ->
     Pos = #cstruct.disc_copies,
     {Cs2, Head2} = set_frag_node(Cs, Pos, Head),
-    set_frag_nodes(NR, ND - 1, NDO, Cs2, Tail, [Head2 | Acc]); 
-set_frag_nodes(NR, ND, NDO, Cs, [Head | Tail], Acc) when NDO > 0 ->
+    set_frag_nodes(NR, ND - 1, NDO, NExt, Cs2, Tail, [Head2 | Acc]);
+set_frag_nodes(NR, ND, NDO, NExt, Cs, [Head | Tail], Acc) when NDO > 0 ->
     Pos = #cstruct.disc_only_copies,
     {Cs2, Head2} = set_frag_node(Cs, Pos, Head),
-    set_frag_nodes(NR, ND, NDO - 1, Cs2, Tail, [Head2 | Acc]); 
-set_frag_nodes(0, 0, 0, Cs, RestDist, ModDist) ->
+    set_frag_nodes(NR, ND, NDO - 1, NExt, Cs2, Tail, [Head2 | Acc]);
+set_frag_nodes(NR, ND, NDO, NExt, Cs, [Head | Tail], Acc) when NExt > 0 ->
+    Pos = #cstruct.external_copies,
+    {Cs2, Head2} = set_frag_node(Cs, Pos, Head),
+    set_frag_nodes(NR, ND, NDO, NExt - 1, Cs2, Tail, [Head2 | Acc]);
+set_frag_nodes(0, 0, 0, 0, Cs, RestDist, ModDist) ->
     {Cs, ModDist, RestDist};
-set_frag_nodes(_, _, _, Cs, [], _) ->
+set_frag_nodes(_, _, _, _, Cs, [], _) ->
     mnesia:abort({combine_error,  Cs#cstruct.name, "Too few nodes in node_pool"}).
 
 set_frag_node(Cs, Pos, Head) ->
@@ -838,13 +852,15 @@ make_add_frag(Tab, SortedNs) ->
     NR = length(Cs#cstruct.ram_copies), 
     ND = length(Cs#cstruct.disc_copies), 
     NDO = length(Cs#cstruct.disc_only_copies),
+    NExt = length(Cs#cstruct.external_copies),
     NewCs = Cs#cstruct{name = NewFrag,
 		       frag_properties = [{base_table, Tab}],
 		       ram_copies = [],
 		       disc_copies = [],
-		       disc_only_copies = []},
+		       disc_only_copies = [],
+                       external_copies = []},
     
-    {NewCs2, _, _} = set_frag_nodes(NR, ND, NDO, NewCs, SortedNs, []),
+    {NewCs2, _, _} = set_frag_nodes(NR, ND, NDO, NExt, NewCs, SortedNs, []),
     [NewOp] = mnesia_schema:make_create_table(NewCs2),
 
     SplitOps = split(Tab, FH2, FromIndecies, FragNames, []),
@@ -886,17 +902,19 @@ adjust_before_split(FH) ->
 		HashMod:add_frag(HashState)
 	end,
     N = FH#frag_state.n_fragments + 1,
-    FromFrags2 = (catch lists:sort(FromFrags)),
-    UnionFrags = (catch lists:merge(FromFrags2, lists:sort(AdditionalWriteFrags))),
     VerifyFun = fun(F) when is_integer(F), F >= 1, F =< N -> false;
 		   (_F) -> true
 		end,
-    case catch lists:filter(VerifyFun, UnionFrags) of
-	[] ->
-	    FH2 = FH#frag_state{n_fragments = N,
-				hash_state  = HashState2},
-	    {FH2, FromFrags2, UnionFrags};
-	BadFrags ->
+    try
+	FromFrags2 = lists:sort(FromFrags),
+	UnionFrags = lists:merge(FromFrags2, lists:sort(AdditionalWriteFrags)),
+
+	Frags = lists:filter(VerifyFun, UnionFrags),
+	Frags == [] orelse error(Frags),
+	FH2 = FH#frag_state{n_fragments = N,
+			    hash_state  = HashState2},
+	{FH2, FromFrags2, UnionFrags}
+    catch error:BadFrags ->
 	    mnesia:abort({"add_frag: Fragment numbers out of range",
 			  BadFrags, {range, 1, N}})
     end.
@@ -939,7 +957,7 @@ do_split(_FH, _OldN, _FragNames, [], Ops) ->
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Delete a fragment from a fragmented table
-%% and merge its records with an other fragment
+%% and merge its records with another fragment
     
 make_multi_del_frag(Tab) ->
     verify_multi(Tab),
@@ -981,22 +999,24 @@ adjust_before_merge(FH) ->
 		HashMod:del_frag(HashState)
 	end,
     N = FH#frag_state.n_fragments,
-    FromFrags2 = (catch lists:sort(FromFrags)),
-    UnionFrags = (catch lists:merge(FromFrags2, lists:sort(AdditionalWriteFrags))),
     VerifyFun = fun(F) when is_integer(F), F >= 1, F =< N -> false;
 		   (_F) -> true
 		end,
-    case catch lists:filter(VerifyFun, UnionFrags) of
-	[] ->
-	    case lists:member(N, FromFrags2) of
-		true ->
-		    FH2 = FH#frag_state{n_fragments = N - 1,
-					hash_state  = HashState2},
-		    {FH2, FromFrags2, UnionFrags};
+    try
+	FromFrags2 = lists:sort(FromFrags),
+	UnionFrags = lists:merge(FromFrags2, lists:sort(AdditionalWriteFrags)),
+
+	Frags = lists:filter(VerifyFun, UnionFrags),
+	[] == Frags orelse error(Frags),
+	case lists:member(N, FromFrags2) of
+	    true ->
+		FH2 = FH#frag_state{n_fragments = N - 1,
+				    hash_state  = HashState2},
+		{FH2, FromFrags2, UnionFrags};
 		false ->
-		    mnesia:abort({"del_frag: Last fragment number not included", N})
-	    end;
-	BadFrags ->
+		mnesia:abort({"del_frag: Last fragment number not included", N})
+	end
+    catch error:BadFrags ->
 	    mnesia:abort({"del_frag: Fragment numbers out of range",
 			  BadFrags, {range, 1, N}})
     end.
@@ -1141,8 +1161,8 @@ remove_node(Node, Cs) ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason); 
-	Value -> Value 
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
+	Value -> Value
     end.
 
 set_frag_hash(Tab, Props) ->
@@ -1313,7 +1333,8 @@ count_frag([Frag | Frags], Dist) ->
     Dist2 =  incr_nodes(val({Frag, ram_copies}), Dist),
     Dist3 =  incr_nodes(val({Frag, disc_copies}), Dist2),
     Dist4 =  incr_nodes(val({Frag, disc_only_copies}), Dist3),
-    count_frag(Frags, Dist4);
+    Dist5 =  incr_nodes(val({Frag, external_copies}), Dist4),
+    count_frag(Frags, Dist5);
 count_frag([], Dist) ->
     Dist.
 
diff --git a/lib/mnesia/src/mnesia_frag_hash.erl b/lib/mnesia/src/mnesia_frag_hash.erl
index 3dfdb87f30..ae4105382e 100644
--- a/lib/mnesia/src/mnesia_frag_hash.erl
+++ b/lib/mnesia/src/mnesia_frag_hash.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2002-2011. All Rights Reserved.
+%% Copyright Ericsson AB 2002-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_frag_old_hash.erl b/lib/mnesia/src/mnesia_frag_old_hash.erl
index 817bb54eb1..b246c76236 100644
--- a/lib/mnesia/src/mnesia_frag_old_hash.erl
+++ b/lib/mnesia/src/mnesia_frag_old_hash.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2002-2009. All Rights Reserved.
+%% Copyright Ericsson AB 2002-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_index.erl b/lib/mnesia/src/mnesia_index.erl
index 54db45e3ba..c79f790973 100644
--- a/lib/mnesia/src/mnesia_index.erl
+++ b/lib/mnesia/src/mnesia_index.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -22,8 +23,8 @@
 
 -module(mnesia_index).
 -export([read/5,
-	 add_index/5,
-	 delete_index/3,
+	 add_index/6,
+	 delete_index/4,
 	 del_object_index/5,
 	 clear_index/4,
 	 dirty_match_object/3,
@@ -38,25 +39,21 @@
 	 get_index_table/3,
 	 
 	 tab2filename/2,
-	 tab2tmp_filename/2,
 	 init_index/2,
 	 init_indecies/3,
 	 del_transient/2,
 	 del_transient/3,
-	 del_index_table/3]).
+	 del_index_table/3,
 
--import(mnesia_lib, [verbose/2]).
+         index_info/2,
+	 ext_index_instances/1]).
+
+-import(mnesia_lib, [val/1, verbose/2]).
 -include("mnesia.hrl").
 
 -record(index, {setorbag, pos_list}).
 
-val(Var) ->
-    case ?catch_val(Var) of
-	{'EXIT', _ReASoN_} -> mnesia_lib:other_val(Var, _ReASoN_); 
-	_VaLuE_ -> _VaLuE_ 
-    end.
-
-%% read an object list throuh its index table
+%% read an object list through its index table
 %% we assume that table Tab has index on attribute number Pos
 
 read(Tid, Store, Tab, IxKey, Pos) ->
@@ -69,62 +66,103 @@ read(Tid, Store, Tab, IxKey, Pos) ->
 	    ResList
     end.
 
-add_index(Index, Tab, Key, Obj, Old) ->    
-    add_index2(Index#index.pos_list, Index#index.setorbag, Tab, Key, Obj, Old).
-
-add_index2([{Pos, Ixt} |Tail], bag, Tab, K, Obj, OldRecs) ->
-    db_put(Ixt, {element(Pos, Obj), K}),
-    add_index2(Tail, bag, Tab, K, Obj, OldRecs);
-add_index2([{Pos, Ixt} |Tail], Type, Tab, K, Obj, OldRecs) ->
+ext_index_instances(Tab) ->
+    #index{pos_list = PosL} = val({Tab, index_info}),
+    lists:foldr(
+      fun({_, {{ext,Alias,Mod}, Tag}}, Acc) ->
+	      [{Alias, Mod, Tag}|Acc];
+	 (_, Acc) ->
+	      Acc
+      end, [], PosL).
+
+
+add_index(#index{pos_list = PosL, setorbag = SorB},
+	  Storage, Tab, Key, Obj, Old) ->
+    add_index2(PosL, SorB, Storage, Tab, Key, Obj, Old).
+
+add_index2([{{Pos,Type}, Ixt} |Tail], bag, Storage, Tab, K, Obj, OldRecs) ->
+    ValsF = index_vals_f(Storage, Tab, Pos),
+    Vals = ValsF(Obj),
+    put_index_vals(Type, Ixt, Vals, K),
+    add_index2(Tail, bag, Storage, Tab, K, Obj, OldRecs);
+add_index2([{{Pos, Type}, Ixt} |Tail], SorB, Storage, Tab, K, Obj, OldRecs0) ->
     %% Remove old tuples in index if Tab is updated
-    case OldRecs of 
-	undefined -> 
-	    Old = mnesia_lib:db_get(Tab, K),
-	    del_ixes(Ixt, Old, Pos, K);
-	Old -> 
-	    del_ixes(Ixt, Old, Pos, K)
-    end,
-    db_put(Ixt, {element(Pos, Obj), K}),
-    add_index2(Tail, Type, Tab, K, Obj, OldRecs);
-add_index2([], _, _Tab, _K, _Obj, _) -> ok.
-
-delete_index(Index, Tab, K) ->
-    delete_index2(Index#index.pos_list, Tab, K).
-
-delete_index2([{Pos, Ixt} | Tail], Tab, K) ->
-    DelObjs = mnesia_lib:db_get(Tab, K), 
-    del_ixes(Ixt, DelObjs, Pos, K),
-    delete_index2(Tail, Tab, K);
-delete_index2([], _Tab, _K) -> ok.
-
-
-del_ixes(_Ixt, [], _Pos, _L) -> ok;
-del_ixes(Ixt, [Obj | Tail], Pos, Key) ->
-    db_match_erase(Ixt, {element(Pos, Obj), Key}),
-    del_ixes(Ixt, Tail, Pos, Key).
-
-del_object_index(Index, Tab, K, Obj, Old) ->
-    del_object_index2(Index#index.pos_list, Index#index.setorbag, Tab, K, Obj, Old).
-
-del_object_index2([], _, _Tab, _K, _Obj, _Old) -> ok;
-del_object_index2([{Pos, Ixt} | Tail], SoB, Tab, K, Obj, Old) ->
+    ValsF = index_vals_f(Storage, Tab, Pos),    NewVals = ValsF(Obj),
+    OldRecs1 = case OldRecs0 of
+		   undefined -> mnesia_lib:db_get(Storage, Tab, K);
+		   _ -> OldRecs0
+	       end,
+    IdxVal = ValsF(Obj),
+    case [Old || Old <- OldRecs1, ValsF(Old) =/= IdxVal] of
+	[] when OldRecs1 =:= [] -> % Write
+	    put_index_vals(Type, Ixt, NewVals, K),
+	    add_index2(Tail, SorB, Storage, Tab, K, Obj, OldRecs1);
+	[] -> %% when OldRecs1 =/= [] Update without modifying index field
+	    add_index2(Tail, SorB, Storage, Tab, K, Obj, OldRecs1);
+	OldRecs -> %% Update
+	    put_index_vals(Type, Ixt, NewVals, K),
+	    [del_ixes(Type, Ixt, ValsF, OldObj, K) || OldObj <- OldRecs],
+	    add_index2(Tail, SorB, Storage, Tab, K, Obj, OldRecs1)
+    end;
+add_index2([], _, _, _Tab, _K, _Obj, _) -> ok.
+
+delete_index(Index, Storage, Tab, K) ->
+    delete_index2(Index#index.pos_list, Storage, Tab, K).
+
+delete_index2([{{Pos, Type}, Ixt} | Tail], Storage, Tab, K) ->
+    DelObjs = mnesia_lib:db_get(Storage, Tab, K),
+    ValsF = index_vals_f(Storage, Tab, Pos),
+    [del_ixes(Type, Ixt, ValsF, Obj, K) || Obj <- DelObjs],
+    delete_index2(Tail, Storage, Tab, K);
+delete_index2([], _Storage, _Tab, _K) -> ok.
+
+put_index_vals(ordered, Ixt, Vals, K) ->
+    [db_put(Ixt, {{V, K}}) || V <- Vals];
+put_index_vals(bag, Ixt, Vals, K) ->
+    [db_put(Ixt, {V, K}) || V <- Vals].
+
+
+del_ixes(bag, Ixt, ValsF, Obj, Key) ->
+    Vals = ValsF(Obj),
+    [db_match_erase(Ixt, {V, Key}) || V <- Vals];
+del_ixes(ordered, Ixt, ValsF, Obj, Key) ->
+    Vals = ValsF(Obj),
+    [db_erase(Ixt, {V,Key}) || V <- Vals].
+
+del_object_index(#index{pos_list = PosL, setorbag = SorB}, Storage, Tab, K, Obj) ->
+    del_object_index2(PosL, SorB, Storage, Tab, K, Obj).
+
+del_object_index2([], _, _Storage, _Tab, _K, _Obj) -> ok;
+del_object_index2([{{Pos, Type}, Ixt} | Tail], SoB, Storage, Tab, K, Obj) ->
+    ValsF = index_vals_f(Storage, Tab, Pos),
     case SoB of
 	bag -> 
-	    del_object_bag(Tab, K, Obj, Pos, Ixt, Old);
+	    del_object_bag(Type, ValsF, Tab, K, Obj, Ixt);
 	_ -> %% If set remove the tuple in index table
-	    del_ixes(Ixt, [Obj], Pos, K)	
+	    del_ixes(Type, Ixt, ValsF, Obj, K)
+    end,
+    del_object_index2(Tail, SoB, Storage, Tab, K, Obj).
+
+del_object_bag(Type, ValsF, Tab, Key, Obj, Ixt) ->
+    IxKeys = ValsF(Obj),
+    Found = [{X, ValsF(X)} || X <- mnesia_lib:db_get(Tab, Key)],
+    del_object_bag_(IxKeys, Found, Type, Tab, Key, Obj, Ixt).
+
+del_object_bag_([IxK|IxKs], Found, Type, Tab, Key, Obj, Ixt) ->
+    case [X || {X, Ixes} <- Found, lists:member(IxK, Ixes)] of
+        [Old] when Old =:= Obj ->
+	    case Type of
+		bag ->
+                    db_match_erase(Ixt, {IxK, Key});
+		ordered ->
+		    db_erase(Ixt, {{IxK, Key}})
+	    end;
+        _ ->
+	    ok
     end,
-    del_object_index2(Tail, SoB, Tab, K, Obj, Old).
-
-del_object_bag(Tab, Key, Obj, Pos, Ixt, undefined) -> 
-    IxKey = element(Pos, Obj),
-    Old = [X || X <-  mnesia_lib:db_get(Tab, Key), element(Pos, X) =:= IxKey],
-    del_object_bag(Tab, Key, Obj, Pos, Ixt, Old);
-%% If Tab type is bag we need remove index identifier if the object being
-%% deleted was the last one
-del_object_bag(_Tab, Key, Obj, Pos, Ixt, Old) when Old =:= [Obj] ->
-    del_ixes(Ixt, [Obj], Pos, Key);
-del_object_bag(_Tab, _Key, _Obj, _Pos, _Ixt, _Old) -> ok.
+    del_object_bag_(IxKs, Found, Type, Tab, Key, Obj, Ixt);
+del_object_bag_([], _, _, _, _, _, _) ->
+    ok.
 
 clear_index(Index, Tab, K, Obj) ->
     clear_index2(Index#index.pos_list, Tab, K, Obj).
@@ -136,8 +174,9 @@ clear_index2([{_Pos, Ixt} | Tail], Tab, K, Obj) ->
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-dirty_match_object(Tab, Pat, Pos) ->
+dirty_match_object(Tab, Pat, Pos) when is_integer(Pos) ->
     %% Assume that we are on the node where the replica is
+    %% Cannot use index plugins here, as they don't map to match patterns
     case element(2, Pat) of
 	'_' ->
 	    IxKey = element(Pos, Pat),
@@ -159,7 +198,7 @@ realkeys(Tab, Pos, IxKey) ->
     Index = get_index_table(Tab, Pos),
     db_get(Index, IxKey). % a list on the form [{IxKey, RealKey1} , ....
     
-dirty_select(Tab, Spec, Pos) ->
+dirty_select(Tab, Spec, Pos) when is_integer(Pos) ->
     %% Assume that we are on the node where the replica is
     %% Returns the records without applying the match spec
     %% The actual filtering is handled by the caller
@@ -169,59 +208,80 @@ dirty_select(Tab, Spec, Pos) ->
     lists:append([mnesia_lib:db_get(StorageType, Tab, Key) || {_,Key} <- RealKeys]).
 
 dirty_read(Tab, IxKey, Pos) ->
-    ResList = mnesia:dirty_rpc(Tab, ?MODULE, dirty_read2,
-			       [Tab, IxKey, Pos]),
-    case val({Tab, setorbag}) of
-	bag ->
-	    %% Remove all tuples which don't include Ixkey
-	    mnesia_lib:key_search_all(IxKey, Pos, ResList);
-	_ -> 
-	    ResList
-    end.
+    mnesia:dirty_rpc(Tab, ?MODULE, dirty_read2,
+		     [Tab, IxKey, Pos]).
 
 dirty_read2(Tab, IxKey, Pos) ->
-    Ix = get_index_table(Tab, Pos),
-    Keys = db_match(Ix, {IxKey, '$1'}),
-    r_keys(Keys, Tab, []).
-
-r_keys([[H]|T],Tab,Ack) -> 
-    V = mnesia_lib:db_get(Tab, H),
-    r_keys(T, Tab, V ++ Ack);
-r_keys([], _, Ack) ->
-    Ack.
+    #index{pos_list = PosL} = val({Tab, index_info}),
+    Storage = val({Tab, storage_type}),
+    {Type, Ixt} = pick_index(PosL, Tab, Pos),
+    Pat = case Type of
+	      ordered -> [{{{IxKey, '$1'}}, [], ['$1']}];
+	      bag     -> [{{IxKey, '$1'}, [], ['$1']}]
+	  end,
+    Keys = db_select(Ixt, Pat),
+    ValsF = index_vals_f(Storage, Tab, Pos),
+    lists:reverse(
+      lists:foldl(
+	fun(K, Acc) ->
+		lists:foldl(
+		  fun(Obj, Acc1) ->
+			  case lists:member(IxKey, ValsF(Obj)) of
+			      true -> [Obj|Acc1];
+			      false -> Acc1
+			  end
+		  end, Acc, mnesia_lib:db_get(Storage, Tab, K))
+	end, [], Keys)).
+
+pick_index([{{{Pfx,_},IxType}, Ixt}|_], _Tab, {_} = Pfx) ->
+    {IxType, Ixt};
+pick_index([{{Pos,IxType}, Ixt}|_], _Tab, Pos) ->
+    {IxType, Ixt};
+pick_index([_|T], Tab, Pos) ->
+    pick_index(T, Tab, Pos);
+pick_index([], Tab, Pos) ->
+    mnesia:abort({no_exist, Tab, {index, Pos}}).
+
 	    
 
 %%%%%%% Creation, Init and deletion routines for index tables
 %% We can have several indexes on the same table
 %% this can be a fairly costly operation if table is *very* large
 
-tab2filename(Tab, Pos) ->
+tab2filename(Tab, {A}) when is_atom(A) ->
+    mnesia_lib:dir(Tab) ++ "_-" ++ atom_to_list(A) ++ "-.DAT";
+tab2filename(Tab, T) when is_tuple(T) ->
+    tab2filename(Tab, element(1, T));
+tab2filename(Tab, Pos) when is_integer(Pos) ->
     mnesia_lib:dir(Tab) ++ "_" ++ integer_to_list(Pos) ++ ".DAT".
 
-tab2tmp_filename(Tab, Pos) ->
-    mnesia_lib:dir(Tab) ++ "_" ++ integer_to_list(Pos) ++ ".TMP".
-        
 init_index(Tab, Storage) ->
-    PosList = val({Tab, index}),
+    Cs = val({Tab, cstruct}),
+    PosList = Cs#cstruct.index,
     init_indecies(Tab, Storage, PosList).
 
 init_indecies(Tab, Storage, PosList) ->
     case Storage of
 	unknown ->
 	    ignore;
+	{ext, Alias, Mod} ->
+	    init_ext_index(Tab, Storage, Alias, Mod, PosList);
 	disc_only_copies ->
-	    init_disc_index(Tab, PosList);
+	    init_disc_index(Tab, Storage, PosList);
 	ram_copies ->
-	    make_ram_index(Tab, PosList);
+	    make_ram_index(Tab, Storage, PosList);
 	disc_copies ->
-	    make_ram_index(Tab, PosList)
+	    make_ram_index(Tab, Storage, PosList)
     end.
 
 %% works for both ram and disc indexes
 
 del_index_table(_, unknown, _) ->
     ignore;
-del_index_table(Tab, Storage, Pos) ->
+del_index_table(Tab, Storage, {_} = Pos) ->
+    delete_transient_index(Tab, Pos, Storage),
+    mnesia_lib:del({Tab, index}, Pos);
+del_index_table(Tab, Storage, Pos) when is_integer(Pos) ->
     delete_transient_index(Tab, Pos, Storage),
     mnesia_lib:del({Tab, index}, Pos).
 
@@ -229,18 +289,29 @@ del_transient(Tab, Storage) ->
     PosList = val({Tab, index}),
     del_transient(Tab, PosList, Storage).
 
-del_transient(_, [], _) -> done;
+del_transient(_, [], _) -> ok;
 del_transient(Tab, [Pos | Tail], Storage) ->
     delete_transient_index(Tab, Pos, Storage),
     del_transient(Tab, Tail, Storage).
 
+delete_transient_index(Tab, Pos, {ext, Alias, Mod}) ->
+    PosInfo = case Pos of
+		  _ when is_integer(Pos) ->
+		      Cs = val({Tab, cstruct}),
+		      lists:keyfind(Pos, 1, Cs#cstruct.index);
+		  {P, T} -> {P, T}
+	      end,
+    Tag = {Tab, index, PosInfo},
+    Mod:close_table(Alias, Tag),
+    Mod:delete_table(Alias, Tag),
+    del_index_info(Tab, Pos),
+    mnesia_lib:unset({Tab, {index, Pos}});
 delete_transient_index(Tab, Pos, disc_only_copies) ->
     Tag = {Tab, index, Pos},
     mnesia_monitor:unsafe_close_dets(Tag),
-    file:delete(tab2filename(Tab, Pos)),
+    _ = file:delete(tab2filename(Tab, Pos)),
     del_index_info(Tab, Pos), %% Uses val(..)
     mnesia_lib:unset({Tab, {index, Pos}});
-
 delete_transient_index(Tab, Pos, _Storage) ->
     Ixt = val({Tab, {index, Pos}}),
     ?ets_delete_table(Ixt),
@@ -250,12 +321,13 @@ delete_transient_index(Tab, Pos, _Storage) ->
 %%%%% misc functions for the index create/init/delete functions above
 
 %% assuming that the file exists.
-init_disc_index(_Tab, []) ->
+init_disc_index(_Tab, _Storage, []) ->
     done;
-init_disc_index(Tab, [Pos | Tail]) when is_integer(Pos) ->
+init_disc_index(Tab, disc_only_copies, [{Pos,_Pref} | Tail]) ->
+    PosInfo = {Pos, bag},
     Fn = tab2filename(Tab, Pos),
-    IxTag = {Tab, index, Pos},
-    file:delete(Fn),
+    IxTag = {Tab, index, PosInfo},
+    _ = file:delete(Fn),
     Args = [{file, Fn}, {keypos, 1}, {type, bag}],
     mnesia_monitor:open_dets(IxTag, Args),
     Storage = disc_only_copies,
@@ -267,16 +339,59 @@ init_disc_index(Tab, [Pos | Tail]) when is_integer(Pos) ->
     mnesia_lib:db_fixtable(Storage, Tab, true),
     ok = dets:init_table(IxTag, create_fun(Init, Tab, Pos)),
     mnesia_lib:db_fixtable(Storage, Tab, false),
-    mnesia_lib:set({Tab, {index, Pos}}, IxTag),
-    add_index_info(Tab, val({Tab, setorbag}), {Pos, {dets, IxTag}}),
-    init_disc_index(Tab, Tail).
+    mnesia_lib:set({Tab, {index, PosInfo}}, IxTag),
+    add_index_info(Tab, val({Tab, setorbag}), {PosInfo, {dets, IxTag}}),
+    init_disc_index(Tab, Storage, Tail).
+
+init_ext_index(_, _, _, _, []) ->
+    done;
+init_ext_index(Tab, Storage, Alias, Mod, [{Pos,Type} | Tail]) ->
+    PosInfo = {Pos, Type},
+    IxTag = {Tab, index, PosInfo},
+    CS = val({Tab, cstruct}),
+    CsList = mnesia_schema:cs2list(CS),
+    _Res = mnesia_monitor:unsafe_create_external(IxTag, Alias, Mod, CsList),
+    Mod:load_table(Alias, IxTag, init_index, CsList),
+    case Mod:is_index_consistent(Alias, IxTag) of
+        false ->
+	    Mod:index_is_consistent(Alias, IxTag, false),
+	    Mod:match_delete(Alias, IxTag, '_'),
+	    IxValsF = index_vals_f(Storage, Tab, Pos),
+            IxObjF = case Type of
+                         bag     -> fun(IxVal, Key) -> {IxVal, Key} end;
+                         ordered -> fun(IxVal, Key) -> {{IxVal, Key}} end
+                     end,
+            mnesia_lib:db_fixtable(Storage, Tab, true),
+            mnesia_lib:db_foldl(
+	      Storage,
+	      fun(Rec, Acc) ->
+		      Key = element(2, Rec),
+		      lists:foreach(
+			fun(V) ->
+				IxObj = IxObjF(V, Key),
+				Mod:insert(Alias, IxTag, IxObj)
+			end, IxValsF(Rec)),
+		      Acc
+	      end, ok, Tab,
+	      [{'_', [], ['$_']}], 100),
+	    Mod:index_is_consistent(Alias, IxTag, true);
+	true ->
+            ignore
+    end,
+
+    mnesia_lib:set({Tab, {index, PosInfo}}, IxTag),
+
+    add_index_info(Tab, val({Tab, setorbag}), {PosInfo, {Storage, IxTag}}),
+    init_ext_index(Tab, Storage, Alias, Mod, Tail).
 
 create_fun(Cont, Tab, Pos) ->
+    IxF = index_vals_f(disc_only_copies, Tab, Pos),
     fun(read) ->
 	    Data = 
 		case Cont of
 		    {start, KeysPerChunk} ->
-			mnesia_lib:db_init_chunk(disc_only_copies, Tab, KeysPerChunk);
+			mnesia_lib:db_init_chunk(
+			  disc_only_copies, Tab, KeysPerChunk);
 		    '$end_of_table' -> 
 			'$end_of_table';
 		    _Else ->
@@ -286,56 +401,82 @@ create_fun(Cont, Tab, Pos) ->
 		'$end_of_table' ->
 		    end_of_input;
 		{Recs, Next} ->
-		    IdxElems = [{element(Pos, Obj), element(2, Obj)} || Obj <- Recs],
+		    IdxElems = lists:flatmap(
+				 fun(Obj) ->
+					 PrimK = element(2, Obj),
+					 [{V, PrimK} || V <- IxF(Obj)]
+				 end, Recs),
 		    {IdxElems, create_fun(Next, Tab, Pos)}
 	    end;
        (close) ->
 	    ok
     end.
 
-make_ram_index(_, []) -> 
+make_ram_index(_, _, []) ->
     done;
-make_ram_index(Tab, [Pos | Tail]) ->
-    add_ram_index(Tab, Pos),
-    make_ram_index(Tab, Tail).
+make_ram_index(Tab, Storage, [Pos | Tail]) ->
+    add_ram_index(Tab, Storage, Pos),
+    make_ram_index(Tab, Storage, Tail).
 
-add_ram_index(Tab, Pos) when is_integer(Pos) ->
-    verbose("Creating index for ~w ~n", [Tab]),
+add_ram_index(Tab, Storage, {Pos, _Pref}) ->
+    Type = ordered,
+    verbose("Creating index for ~w ~p ~p~n", [Tab, Pos, Type]),
     SetOrBag = val({Tab, setorbag}),
-    IndexType = case SetOrBag of
-        set -> duplicate_bag;
-        ordered_set -> duplicate_bag;
-        bag -> bag
-    end,
-    Index = mnesia_monitor:mktab(mnesia_index, [IndexType, public]),
+    IxValsF = index_vals_f(Storage, Tab, Pos),
+    IxFun = fun(Val, Key) -> {{Val, Key}} end,
+    Index = mnesia_monitor:mktab(mnesia_index, [ordered_set, public]),
     Insert = fun(Rec, _Acc) ->
-		     true = ?ets_insert(Index, {element(Pos, Rec), element(2, Rec)})
+		     PrimK = element(2, Rec),
+		     true = ?ets_insert(
+			       Index, [IxFun(V, PrimK)
+				       || V <- IxValsF(Rec)])
 	     end,
     mnesia_lib:db_fixtable(ram_copies, Tab, true),
-    true = ets:foldl(Insert, true, Tab),
+    true = mnesia_lib:db_foldl(Storage, Insert, true, Tab),
     mnesia_lib:db_fixtable(ram_copies, Tab, false),
     mnesia_lib:set({Tab, {index, Pos}}, Index),
-    add_index_info(Tab, SetOrBag, {Pos, {ram, Index}});
-add_ram_index(_Tab, snmp) ->
+    add_index_info(Tab, SetOrBag, {{Pos, Type}, {ram, Index}});
+add_ram_index(_Tab, _, snmp) ->
     ok.
 
-add_index_info(Tab, Type, IxElem) ->
+index_info(SetOrBag, PosList) ->
+    IxPlugins = mnesia_schema:index_plugins(),
+    ExpPosList = lists:map(
+		   fun({{P,Type},Ixt} = PI) ->
+			   case P of
+			       {_} = IxN ->
+				   {_, M, F} =
+				       lists:keyfind(IxN, 1, IxPlugins),
+				   {{{IxN,M,F}, Type}, Ixt};
+			       _ ->
+				   PI
+			   end
+		   end, PosList),
+    #index{setorbag = SetOrBag, pos_list = ExpPosList}.
+
+add_index_info(Tab, SetOrBag, IxElem) ->
     Commit = val({Tab, commit_work}),
     case lists:keysearch(index, 1, Commit) of
 	false ->
-	    Index = #index{setorbag = Type, 
-			   pos_list = [IxElem]},
-	    %% Check later if mnesia_tm is sensative about the order 
+	    IndexInfo = index_info(SetOrBag, [IxElem]),
+	    %% Check later if mnesia_tm is sensitive about the order
+	    mnesia_lib:set({Tab, index_info}, IndexInfo),
+	    mnesia_lib:set({Tab, index}, index_positions(IndexInfo)),
 	    mnesia_lib:set({Tab, commit_work}, 
-			   mnesia_lib:sort_commit([Index | Commit]));
+			   mnesia_lib:sort_commit([IndexInfo | Commit]));
 	{value, Old} ->
 	    %% We could check for consistency here
 	    Index = Old#index{pos_list = [IxElem | Old#index.pos_list]},
+	    mnesia_lib:set({Tab, index_info}, Index),
+	    mnesia_lib:set({Tab, index}, index_positions(Index)),
 	    NewC = lists:keyreplace(index, 1, Commit, Index),
 	    mnesia_lib:set({Tab, commit_work}, 
 			   mnesia_lib:sort_commit(NewC))
     end.
 
+index_positions(#index{pos_list = PL}) ->
+    [P || {{P,_},_} <- PL].
+
 del_index_info(Tab, Pos) ->
     Commit = val({Tab, commit_work}),
     case lists:keysearch(index, 1, Commit) of
@@ -343,13 +484,21 @@ del_index_info(Tab, Pos) ->
 	    %% Something is wrong ignore
 	    skip;
 	{value, Old} ->
-	    case lists:keydelete(Pos, 1, Old#index.pos_list) of
+	    case lists:filter(fun({P,_}) ->
+                                      element(1,P)=/=Pos
+                              end,
+                              Old#index.pos_list) of
 		[] -> 
+                    IndexInfo = index_info(Old#index.setorbag,[]),
+		    mnesia_lib:set({Tab, index_info}, IndexInfo),
+		    mnesia_lib:set({Tab, index}, index_positions(IndexInfo)),
 		    NewC = lists:keydelete(index, 1, Commit),
 		    mnesia_lib:set({Tab, commit_work}, 
 				   mnesia_lib:sort_commit(NewC));
 		New ->
 		    Index = Old#index{pos_list = New},
+		    mnesia_lib:set({Tab, index_info}, Index),
+		    mnesia_lib:set({Tab, index}, index_positions(Index)),
 		    NewC = lists:keyreplace(index, 1, Commit, Index),
 		    mnesia_lib:set({Tab, commit_work}, 
 				   mnesia_lib:sort_commit(NewC))
@@ -358,33 +507,69 @@ del_index_info(Tab, Pos) ->
 
 db_put({ram, Ixt}, V) ->
     true = ?ets_insert(Ixt, V);
+db_put({{ext, _, _} = Ext, Ixt}, V) ->
+    mnesia_lib:db_put(Ext, Ixt, V);
 db_put({dets, Ixt}, V) ->
     ok = dets:insert(Ixt, V).
 
-db_get({ram, Ixt}, K) ->
-    ?ets_lookup(Ixt, K);
+db_get({ram, _}=Ixt, IxKey) ->
+    Pat = [{{{IxKey, '$1'}}, [], [{element, 1, '$_'}]}],
+    db_select(Ixt, Pat);
+db_get({{ext,_,_} = _Storage, {_,_,{_,Type}}} = Ixt, IxKey) ->
+    Pat = case Type of
+	      ordered -> [{{{IxKey, '$1'}}, [], [{element, 1, '$_'}]}];
+	      bag     -> [{{IxKey, '_'}, [], ['$_']}]
+	  end,
+    db_select(Ixt, Pat);
 db_get({dets, Ixt}, K) ->
     dets:lookup(Ixt, K).
 
+db_erase({ram, Ixt}, K) ->
+    ?ets_delete(Ixt, K);
+db_erase({{ext,_,_} = Ext, Ixt}, K) ->
+    mnesia_lib:db_erase(Ext, Ixt, K);
+db_erase({dets, Ixt}, K) ->
+    dets:delete(Ixt, K).
+
 db_match_erase({ram, Ixt}, Pat) ->
     true = ?ets_match_delete(Ixt, Pat);
+db_match_erase({{ext,_,_} = Ext, Ixt}, Pat) ->
+    mnesia_lib:db_match_erase(Ext, Ixt, Pat);
 db_match_erase({dets, Ixt}, Pat) ->
     ok = dets:match_delete(Ixt, Pat).
     
-db_match({ram, Ixt}, Pat) ->
-    ?ets_match(Ixt, Pat);
-db_match({dets, Ixt}, Pat) ->
-    dets:match(Ixt, Pat).
+db_select({ram, Ixt}, Pat) ->
+    ets:select(Ixt, Pat);
+db_select({{ext,_,_} = Ext, Ixt}, Pat) ->
+    mnesia_lib:db_select(Ext, Ixt, Pat);
+db_select({dets, Ixt}, Pat) ->
+    dets:select(Ixt, Pat).
+
     
 get_index_table(Tab, Pos) ->
     get_index_table(Tab,  val({Tab, storage_type}), Pos).
 
-get_index_table(Tab, ram_copies, Pos) ->
-    {ram,  val({Tab, {index, Pos}})};
-get_index_table(Tab, disc_copies, Pos) ->
-    {ram,  val({Tab, {index, Pos}})};
-get_index_table(Tab, disc_only_copies, Pos) ->
-    {dets, val({Tab, {index, Pos}})};
-get_index_table(_Tab, unknown, _Pos) ->
-    unknown.
-
+get_index_table(Tab, _Storage, Pos) ->
+    #index{pos_list = PosL} = val({Tab, index_info}),
+    {_IxType, Ixt} = pick_index(PosL, Tab, Pos),
+    Ixt.
+
+index_vals_f(Storage, Tab, {_} = Pos) ->
+    index_vals_f(Storage, Tab,
+		 lists:keyfind(Pos, 1, mnesia_schema:index_plugins()));
+index_vals_f(_Storage, Tab, {Pos,M,F}) ->
+    fun(Obj) ->
+	    M:F(Tab, Pos, Obj)
+    end;
+index_vals_f(Storage, Tab, Pos) when is_integer(Pos) ->
+    case mnesia_lib:semantics(Storage, index_fun) of
+	undefined ->
+	    fun(Obj) ->
+		    [element(Pos, Obj)]
+	    end;
+	F when is_function(F, 4) ->
+	    {ext, Alias, _Mod} = Storage,
+	    fun(Obj) ->
+		    F(Alias, Tab, Pos, Obj)
+	    end
+    end.
diff --git a/lib/mnesia/src/mnesia_kernel_sup.erl b/lib/mnesia/src/mnesia_kernel_sup.erl
index 08f6129fc0..c9af5c460a 100644
--- a/lib/mnesia/src/mnesia_kernel_sup.erl
+++ b/lib/mnesia/src/mnesia_kernel_sup.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_late_loader.erl b/lib/mnesia/src/mnesia_late_loader.erl
index d09de3ca66..e273329ffc 100644
--- a/lib/mnesia/src/mnesia_late_loader.erl
+++ b/lib/mnesia/src/mnesia_late_loader.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1998-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -36,17 +37,19 @@
 
 -define(SERVER_NAME, ?MODULE).
 
+-include("mnesia.hrl").
+
 -record(state, {supervisor}).
 
 async_late_disc_load(_, [], _) -> ok;
 async_late_disc_load(Node, Tabs, Reason) ->
     Msg = {async_late_disc_load, Tabs, Reason},
-    catch ({?SERVER_NAME, Node} ! {self(), Msg}).
+    ?SAFE({?SERVER_NAME, Node} ! {self(), Msg}).
 
 maybe_async_late_disc_load(_, [], _) -> ok;
 maybe_async_late_disc_load(Node, Tabs, Reason) ->
     Msg = {maybe_async_late_disc_load, Tabs, Reason},
-    catch ({?SERVER_NAME, Node} ! {self(), Msg}).
+    ?SAFE({?SERVER_NAME, Node} ! {self(), Msg}).
 
 start() ->
     mnesia_monitor:start_proc(?SERVER_NAME, ?MODULE, init, [self()]).
diff --git a/lib/mnesia/src/mnesia_lib.erl b/lib/mnesia/src/mnesia_lib.erl
index ae6631646c..10e232c800 100644
--- a/lib/mnesia/src/mnesia_lib.erl
+++ b/lib/mnesia/src/mnesia_lib.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -53,6 +54,7 @@
 	 db_erase_tab/2,
 	 db_first/1,
 	 db_first/2,
+	 db_foldl/3, db_foldl/4, db_foldl/6,
 	 db_last/1,
 	 db_last/2,
 	 db_fixtable/3,
@@ -114,7 +116,7 @@
 	 lock_table/1,
 	 mkcore/1,
 	 not_active_here/1,
-	 other_val/2,
+         other_val/1,
          overload_read/0,
          overload_read/1,
          overload_set/2,
@@ -134,6 +136,7 @@
 	 set_local_content_whereabouts/1,
 	 set_remote_where_to_read/1,
 	 set_remote_where_to_read/2,
+	 semantics/2,
 	 show/1,
 	 show/2,
 	 sort_commit/1,
@@ -143,6 +146,7 @@
 	 tab2tmp/1,
 	 tab2dcd/1,
 	 tab2dcl/1,
+	 tab2logtmp/1,
 	 to_list/1,
 	 union/2,
 	 uniq/1,
@@ -150,6 +154,8 @@
 	 unset/1,
 	 %% update_counter/2,
 	 val/1,
+	 validate_key/2,
+	 validate_record/2,
 	 vcore/0,
 	 vcore/1,
 	 verbose/2,
@@ -296,11 +302,7 @@ active_here(Tab) ->
 not_active_here(Tab) ->
     not active_here(Tab).
 
-exists(Fname) ->
-    case file:open(Fname, [raw,read]) of
-	{ok, F} ->file:close(F), true;
-	_ -> false
-    end.
+exists(Fname) -> filelib:is_regular(Fname).
 
 dir() -> mnesia_monitor:get_env(dir).
 
@@ -322,15 +324,41 @@ tab2dcd(Tab) ->  %% Disc copies data
 tab2dcl(Tab) ->  %% Disc copies log
     dir(lists:concat([Tab, ".DCL"])).
 
+tab2logtmp(Tab) ->  %% Disc copies log
+    dir(lists:concat([Tab, ".LOGTMP"])).
+
 storage_type_at_node(Node, Tab) ->
     search_key(Node, [{disc_copies, val({Tab, disc_copies})},
 		      {ram_copies, val({Tab, ram_copies})},
-		      {disc_only_copies, val({Tab, disc_only_copies})}]).
+		      {disc_only_copies, val({Tab, disc_only_copies})}|
+		      wrap_external(val({Tab, external_copies}))]).
 
 cs_to_storage_type(Node, Cs) ->
     search_key(Node, [{disc_copies, Cs#cstruct.disc_copies},
 		      {ram_copies, Cs#cstruct.ram_copies},
-		      {disc_only_copies, Cs#cstruct.disc_only_copies}]).
+		      {disc_only_copies, Cs#cstruct.disc_only_copies} |
+                      wrap_external(Cs#cstruct.external_copies)]).
+
+-define(native(T), T==ram_copies; T==disc_copies; T==disc_only_copies).
+
+semantics({ext,Alias,Mod}, Item) ->
+    Mod:semantics(Alias, Item);
+semantics({Alias,Mod}, Item) ->
+    Mod:semantics(Alias, Item);
+semantics(Type, storage) when ?native(Type) ->
+    Type;
+semantics(Type, types) when ?native(Type) ->
+    [set, ordered_set, bag];
+semantics(disc_only_copies, index_types) ->
+    [bag];
+semantics(Type, index_types) when ?native(Type) ->
+    [bag, ordered];
+semantics(_, _) ->
+    undefined.
+
+
+wrap_external(L) ->
+    [{{ext,Alias,Mod},Ns} || {{Alias,Mod},Ns} <- L].
 
 schema_cs_to_storage_type(Node, Cs) ->
     case cs_to_storage_type(Node, Cs) of
@@ -338,7 +366,6 @@ schema_cs_to_storage_type(Node, Cs) ->
 	Other -> Other
     end.
 
-
 search_key(Key, [{Val, List} | Tail]) ->
     case lists:member(Key, List) of
 	true -> Val;
@@ -347,6 +374,33 @@ search_key(Key, [{Val, List} | Tail]) ->
 search_key(_Key, []) ->
     unknown.
 
+validate_key(Tab, Key) ->
+    case ?catch_val({Tab, record_validation}) of
+	{RecName, Arity, Type} ->
+	    {RecName, Arity, Type};
+	{RecName, Arity, Type, Alias, Mod} ->
+	    %% external type
+	    Mod:validate_key(Alias, Tab, RecName, Arity, Type, Key);
+	{'EXIT', _} ->
+	    mnesia:abort({no_exists, Tab})
+    end.
+
+
+validate_record(Tab, Obj) ->
+    case ?catch_val({Tab, record_validation}) of
+	{RecName, Arity, Type}
+	  when tuple_size(Obj) == Arity, RecName == element(1, Obj) ->
+	    {RecName, Arity, Type};
+	{RecName, Arity, Type, Alias, Mod}
+	  when tuple_size(Obj) == Arity, RecName == element(1, Obj) ->
+	    %% external type
+	    Mod:validate_record(Alias, Tab, RecName, Arity, Type, Obj);
+	{'EXIT', _} ->
+	    mnesia:abort({no_exists, Tab});
+	_ ->
+	    mnesia:abort({bad_type, Obj})
+    end.
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% ops, we've got some global variables here :-)
 
@@ -382,8 +436,8 @@ search_key(_Key, []) ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', _ReASoN_} -> mnesia_lib:other_val(Var, _ReASoN_); 
-	_VaLuE_ -> _VaLuE_ 
+	{'EXIT', _} -> other_val(Var);
+	_VaLuE_ -> _VaLuE_
     end.
 
 set(Var, Val) ->
@@ -392,32 +446,31 @@ set(Var, Val) ->
 unset(Var) ->
     ?ets_delete(mnesia_gvar, Var).
 
-other_val(Var, Other) ->
+other_val(Var) ->
+    case other_val_1(Var) of
+        error -> pr_other(Var);
+        Val -> Val
+    end.
+
+other_val_1(Var) ->
     case Var of
 	{_, where_to_read} -> nowhere;
 	{_, where_to_write} -> [];
 	{_, active_replicas} -> [];
-	_ ->
-	    pr_other(Var, Other)
+	_ -> error
     end.
 
--spec pr_other(_,_) -> no_return().
-
-pr_other(Var, Other) ->
-    Why = 
+-spec pr_other(_) -> no_return().
+pr_other(Var) ->
+    Why =
 	case is_running() of
 	    no -> {node_not_running, node()};
 	    _ -> {no_exists, Var}
 	end,
     verbose("~p (~p) val(mnesia_gvar, ~w) -> ~p ~p ~n",
 	    [self(), process_info(self(), registered_name),
-	     Var, Other, Why]),
-    case Other of
-	{badarg, [{ets, lookup_element, _, _}|_]} ->
-	    exit(Why);
-	_ ->
-	    erlang:error(Why)
-    end.
+	     Var, Why, erlang:get_stacktrace()]),
+    mnesia:abort(Why).
 
 %% Some functions for list valued variables
 add(Var, Val) ->
@@ -553,10 +606,16 @@ read_counter(Name) ->
     ?ets_lookup_element(mnesia_stats, Name, 2).
 
 cs_to_nodes(Cs) ->
+    ext_nodes(Cs#cstruct.external_copies) ++
     Cs#cstruct.disc_only_copies ++
     Cs#cstruct.disc_copies ++
     Cs#cstruct.ram_copies.
 
+ext_nodes(Ext) ->
+    lists:flatmap(fun({_, Ns}) ->
+			  Ns
+		  end, Ext).
+
 overload_types() ->
     [mnesia_tm, mnesia_dump_log].
 
@@ -596,7 +655,7 @@ coredump(CrashInfo) ->
     Core = mkcore(CrashInfo),
     Out = core_file(),
     important("Writing Mnesia core to file: ~p...~p~n", [Out, CrashInfo]),
-    file:write_file(Out, Core),
+    _ = file:write_file(Out, Core),
     Out.
 
 core_file() ->
@@ -620,7 +679,7 @@ mkcore(CrashInfo) ->
     Core = [
 	    CrashInfo,
 	    {time, {date(), time()}},
-	    {self, catch process_info(self())},
+	    {self, proc_dbg_info(self())},
 	    {nodes, catch rpc:multicall(Nodes, ?MODULE, get_node_number, [])},
 	    {applications, catch lists:sort(application:loaded_applications())},
 	    {flags, catch init:get_arguments()},
@@ -697,7 +756,7 @@ relatives() ->
     Info = fun(Name) ->
 		   case whereis(Name) of
 		       undefined -> false;
-		       Pid -> {true, {Name, Pid, catch process_info(Pid)}}
+		       Pid -> {true, {Name, Pid, proc_dbg_info(Pid)}}
 		   end
 	   end,
     lists:zf(Info, mnesia:ms()).
@@ -706,14 +765,14 @@ workers({workers, Loaders, Senders, Dumper}) ->
     Info = fun({Pid, {send_table, Tab, _Receiver, _St}}) ->
 		   case Pid of
 		       undefined -> false;
-		       Pid -> {true, {Pid, Tab, catch process_info(Pid)}}
+		       Pid -> {true, {Pid, Tab, proc_dbg_info(Pid)}}
 		   end;
 	      ({Pid, What}) when is_pid(Pid) ->
-		   {true, {Pid, What, catch process_info(Pid)}};
+		   {true, {Pid, What, proc_dbg_info(Pid)}};
 	      ({Name, Pid}) ->
 		   case Pid of
 		       undefined -> false;
-		       Pid -> {true, {Name, Pid, catch process_info(Pid)}}
+		       Pid -> {true, {Name, Pid, proc_dbg_info(Pid)}}
 		   end
 	   end,
     SInfo = lists:zf(Info, Senders),
@@ -727,13 +786,21 @@ locking_procs(LockList) when is_list(LockList) ->
 		   Pid = Tid#tid.pid,
 		   case node(Pid) == node() of
 		       true -> 
-			   {true, {Pid, catch process_info(Pid)}};
+			   {true, {Pid, proc_dbg_info(Pid)}};
 		       _ ->
 			   false
 		   end
 	   end,
     lists:zf(Info, UT).
 
+proc_dbg_info(Pid) ->
+    try
+	[process_info(Pid, current_stacktrace)|
+	 process_info(Pid)]
+    catch _:R ->
+	    [{process_info,crashed,R}]
+    end.
+
 view() ->
     Bin = mkcore({crashinfo, {"view only~n", []}}),
     vcore(Bin).
@@ -744,7 +811,7 @@ view(File) ->
 	true ->
 	    view(File, dat);
 	false ->
-	    case suffix([".LOG", ".BUP", ".ETS"], File) of
+	    case suffix([".LOG", ".BUP", ".ETS", ".LOGTMP"], File) of
 		true ->
 		    view(File, log);
 		false ->
@@ -806,9 +873,9 @@ vcore(File) ->
 
 vcore_elem({schema_file, {ok, B}}) ->
     Fname = "/tmp/schema.DAT",
-    file:write_file(Fname, B),
-    dets:view(Fname),
-    file:delete(Fname);
+    _ = file:write_file(Fname, B),
+    _ = dets:view(Fname),
+    _ = file:delete(Fname);
 
 vcore_elem({logfile, {ok, BinList}}) ->
     Fun = fun({F, Info}) ->
@@ -896,7 +963,7 @@ dirty_rpc_error_tag(Reason) ->
     end.
 
 fatal(Format, Args) ->
-    catch set(mnesia_status, stopping),
+    ?SAFE(catch set(mnesia_status, stopping)),
     Core = mkcore({crashinfo, {Format, Args}}),
     report_fatal(Format, Args, Core),
     timer:sleep(10000), % Enough to write the core dump to disc?
@@ -908,7 +975,7 @@ report_fatal(Format, Args) ->
 
 report_fatal(Format, Args, Core) ->
     report_system_event({mnesia_fatal, Format, Args, Core}),
-    catch exit(whereis(mnesia_monitor), fatal).
+    ?SAFE(exit(whereis(mnesia_monitor), fatal)).
 
 %% We sleep longer and longer the more we try
 %% Made some testing and came up with the following constants
@@ -918,19 +985,7 @@ random_time(Retries, _Counter0) ->
     UpperLimit = 500,
     Dup = Retries * Retries,
     MaxIntv = trunc(UpperLimit * (1-(50/((Dup)+50)))),
-    
-    case get(random_seed) of
-	undefined ->
-	    {X, Y, Z} = erlang:now(), %% time()
-	    random:seed(X, Y, Z),
-	    Time = Dup + random:uniform(MaxIntv),
-	    %%	    dbg_out("---random_test rs ~w max ~w val ~w---~n", [Retries, MaxIntv, Time]),
-	    Time;
-	_ ->
-	    Time = Dup + random:uniform(MaxIntv),
-	    %%	    dbg_out("---random_test rs ~w max ~w val ~w---~n", [Retries, MaxIntv, Time]),
-	    Time	    
-    end.
+    Dup + rand:uniform(MaxIntv).
 
 report_system_event(Event0) ->
     Event = {mnesia_system_event, Event0},
@@ -958,20 +1013,17 @@ report_system_event({'EXIT', Reason}, Event) ->
 	    unlink(Pid),
 
             %% We get an exit signal if server dies
-            receive
-                {'EXIT', Pid, _Reason} ->
-                    {error, {node_not_running, node()}}
-            after 0 ->
-		    gen_event:stop(mnesia_event),
-                    ok
+            receive {'EXIT', Pid, _Reason} -> ok
+            after 0 -> gen_event:stop(mnesia_event)
             end;
 
 	Error ->
 	    Msg = "Mnesia(~p): Cannot report event ~p: ~p (~p)~n",
 	    error_logger:format(Msg, [node(), Event, Reason, Error])
-    end;
+    end,
+    ok;
 report_system_event(_Res, _Event) ->
-    ignore.
+    ok.
 
 %% important messages are reported regardless of debug level
 important(Format, Args) ->
@@ -1007,7 +1059,7 @@ dbg_out(Format, Args) ->
 
 %% Keep the last 10 debug print outs
 save(DbgInfo) ->
-    catch save2(DbgInfo).
+    ?SAFE(save2(DbgInfo)).
 
 save2(DbgInfo) ->
     Key = {'$$$_report', current_pos},
@@ -1025,8 +1077,8 @@ copy_file(From, To) ->
 	    case file:open(To, [raw, binary, write]) of
 		{ok, T} ->
 		    Res = copy_file_loop(F, T, 8000),
-		    file:close(F),
-		    file:close(T),
+		    ok = file:close(F),
+		    ok = file:close(T),
 		    Res;
 		{error, Reason} ->
 		    {error, Reason}
@@ -1038,7 +1090,7 @@ copy_file(From, To) ->
 copy_file_loop(F, T, ChunkSize) ->
     case file:read(F, ChunkSize) of
 	{ok, Bin} ->
-	    file:write(T, Bin),
+	    ok = file:write(T, Bin),
 	    copy_file_loop(F, T, ChunkSize);
 	eof ->
 	    ok;
@@ -1055,18 +1107,24 @@ db_get(Tab, Key) ->
     db_get(val({Tab, storage_type}), Tab, Key).
 db_get(ram_copies, Tab, Key) -> ?ets_lookup(Tab, Key);
 db_get(disc_copies, Tab, Key) -> ?ets_lookup(Tab, Key);
-db_get(disc_only_copies, Tab, Key) -> dets:lookup(Tab, Key).
+db_get(disc_only_copies, Tab, Key) -> dets:lookup(Tab, Key);
+db_get({ext, Alias, Mod}, Tab, Key) ->
+    Mod:lookup(Alias, Tab, Key).
 
 db_init_chunk(Tab) ->
     db_init_chunk(val({Tab, storage_type}), Tab, 1000).
 db_init_chunk(Tab, N) ->
     db_init_chunk(val({Tab, storage_type}), Tab, N).
 
+db_init_chunk({ext, Alias, Mod}, Tab, N) ->
+    Mod:select(Alias, Tab, [{'_', [], ['$_']}], N);
 db_init_chunk(disc_only_copies, Tab, N) ->
     dets:select(Tab, [{'_', [], ['$_']}], N);
 db_init_chunk(_, Tab, N) ->
     ets:select(Tab, [{'_', [], ['$_']}], N).
 
+db_chunk({ext, _Alias, Mod}, State) ->
+    Mod:select(State);
 db_chunk(disc_only_copies, State) ->
     dets:select(State);
 db_chunk(_, State) ->
@@ -1077,46 +1135,82 @@ db_put(Tab, Val) ->
 
 db_put(ram_copies, Tab, Val) -> ?ets_insert(Tab, Val), ok;
 db_put(disc_copies, Tab, Val) -> ?ets_insert(Tab, Val), ok;
-db_put(disc_only_copies, Tab, Val) -> dets:insert(Tab, Val).
+db_put(disc_only_copies, Tab, Val) -> dets:insert(Tab, Val);
+db_put({ext, Alias, Mod}, Tab, Val) ->
+    Mod:insert(Alias, Tab, Val).
 
 db_match_object(Tab, Pat) ->
     db_match_object(val({Tab, storage_type}), Tab, Pat).
 db_match_object(Storage, Tab, Pat) ->
     db_fixtable(Storage, Tab, true),
-    Res = catch_match_object(Storage, Tab, Pat),
-    db_fixtable(Storage, Tab, false),
-    case Res of
-	{'EXIT', Reason} -> exit(Reason);
-	_ -> Res
+    try
+	case Storage of
+	    disc_only_copies -> dets:match_object(Tab, Pat);
+	    {ext, Alias, Mod} -> Mod:select(Alias, Tab, [{Pat, [], ['$_']}]);
+	    _ -> ets:match_object(Tab, Pat)
+	end
+    after
+	db_fixtable(Storage, Tab, false)
     end.
 
-catch_match_object(disc_only_copies, Tab, Pat) ->
-    catch dets:match_object(Tab, Pat);
-catch_match_object(_, Tab, Pat) ->
-    catch ets:match_object(Tab, Pat).
+db_foldl(Fun, Acc, Tab) ->
+    db_foldl(val({Tab, storage_type}), Fun, Acc, Tab).
+
+db_foldl(Storage, Fun, Acc, Tab) ->
+    Limit = mnesia_monitor:get_env(fold_chunk_size),
+    db_foldl(Storage, Fun, Acc, Tab, [{'_', [], ['$_']}], Limit).
+
+db_foldl(ram_copies, Fun, Acc, Tab, Pat, Limit) ->
+    mnesia_lib:db_fixtable(ram_copies, Tab, true),
+    try select_foldl(db_select_init(ram_copies, Tab, Pat, Limit),
+		     Fun, Acc, ram_copies)
+    after
+	mnesia_lib:db_fixtable(ram_copies, Tab, false)
+    end;
+db_foldl(Storage, Fun, Acc, Tab, Pat, Limit) ->
+    select_foldl(mnesia_lib:db_select_init(Storage, Tab, Pat, Limit), Fun, Acc, Storage).
+
+select_foldl({Objs, Cont}, Fun, Acc, Storage) ->
+    select_foldl(mnesia_lib:db_select_cont(Storage, Cont, []),
+	      Fun, lists:foldl(Fun, Acc, Objs), Storage);
+select_foldl('$end_of_table', _, Acc, _) ->
+    Acc.
 
 db_select(Tab, Pat) ->
     db_select(val({Tab, storage_type}), Tab, Pat).
 
 db_select(Storage, Tab, Pat) ->
     db_fixtable(Storage, Tab, true),
-    Res = catch_select(Storage, Tab, Pat),
-    db_fixtable(Storage, Tab, false),
-    case Res of
-	{'EXIT', Reason} -> exit(Reason);
-	_ -> Res
+    try
+	case Storage of
+	    disc_only_copies -> dets:select(Tab, Pat);
+	    {ext, Alias, Mod} -> Mod:select(Alias, Tab, Pat);
+	    _ -> ets:select(Tab, Pat)
+	end
+    after
+	db_fixtable(Storage, Tab, false)
     end.
 
-catch_select(disc_only_copies, Tab, Pat) ->
-    catch dets:select(Tab, Pat);
-catch_select(_, Tab, Pat) ->
-    catch ets:select(Tab, Pat).
-
+db_select_init({ext, Alias, Mod}, Tab, Pat, Limit) ->
+    case Mod:select(Alias, Tab, Pat, Limit) of
+	{Matches, Continuation} when is_list(Matches) ->
+	    {Matches, {Alias, Continuation}};
+	R ->
+	    R
+    end;
 db_select_init(disc_only_copies, Tab, Pat, Limit) ->
     dets:select(Tab, Pat, Limit);
 db_select_init(_, Tab, Pat, Limit) ->
     ets:select(Tab, Pat, Limit).
 
+db_select_cont({ext, Alias, Mod}, Cont0, Ms) ->
+    Cont = Mod:repair_continuation(Cont0, Ms),
+    case Mod:select(Cont) of
+	{Matches, Continuation} when is_list(Matches) ->
+	    {Matches, {Alias, Continuation}};
+	R ->
+	    R
+    end;
 db_select_cont(disc_only_copies, Cont0, Ms) ->
     Cont = dets:repair_continuation(Cont0, Ms),
     dets:select(Cont);
@@ -1133,13 +1227,18 @@ db_fixtable(disc_copies, Tab, Bool) ->
 db_fixtable(dets, Tab, Bool) ->
     dets:safe_fixtable(Tab, Bool);
 db_fixtable(disc_only_copies, Tab, Bool) ->
-    dets:safe_fixtable(Tab, Bool).
+    dets:safe_fixtable(Tab, Bool);
+db_fixtable({ext, Alias, Mod}, Tab, Bool) ->
+    Mod:fixtable(Alias, Tab, Bool).
 
 db_erase(Tab, Key) ->
     db_erase(val({Tab, storage_type}), Tab, Key).
 db_erase(ram_copies, Tab, Key) -> ?ets_delete(Tab, Key), ok;
 db_erase(disc_copies, Tab, Key) -> ?ets_delete(Tab, Key), ok;
-db_erase(disc_only_copies, Tab, Key) -> dets:delete(Tab, Key).
+db_erase(disc_only_copies, Tab, Key) -> dets:delete(Tab, Key);
+db_erase({ext, Alias, Mod}, Tab, Key) ->
+    Mod:delete(Alias, Tab, Key),
+    ok.
 
 db_match_erase(Tab, '_') ->
     db_delete_all(val({Tab, storage_type}),Tab);
@@ -1147,7 +1246,10 @@ db_match_erase(Tab, Pat) ->
     db_match_erase(val({Tab, storage_type}), Tab, Pat).
 db_match_erase(ram_copies, Tab, Pat) -> ?ets_match_delete(Tab, Pat), ok;
 db_match_erase(disc_copies, Tab, Pat) -> ?ets_match_delete(Tab, Pat), ok;
-db_match_erase(disc_only_copies, Tab, Pat) -> dets:match_delete(Tab, Pat).
+db_match_erase(disc_only_copies, Tab, Pat) -> dets:match_delete(Tab, Pat);
+db_match_erase({ext, Alias, Mod}, Tab, Pat) ->
+    Mod:match_delete(Alias, Tab, Pat),
+    ok.
 
 db_delete_all(ram_copies, Tab) ->       ets:delete_all_objects(Tab);
 db_delete_all(disc_copies, Tab) ->      ets:delete_all_objects(Tab);
@@ -1157,31 +1259,41 @@ db_first(Tab) ->
     db_first(val({Tab, storage_type}), Tab).
 db_first(ram_copies, Tab) -> ?ets_first(Tab);
 db_first(disc_copies, Tab) -> ?ets_first(Tab);
-db_first(disc_only_copies, Tab) -> dets:first(Tab).
+db_first(disc_only_copies, Tab) -> dets:first(Tab);
+db_first({ext, Alias, Mod}, Tab) ->
+    Mod:first(Alias, Tab).
 
 db_next_key(Tab, Key) ->
     db_next_key(val({Tab, storage_type}), Tab, Key).
 db_next_key(ram_copies, Tab, Key) -> ?ets_next(Tab, Key);
 db_next_key(disc_copies, Tab, Key) -> ?ets_next(Tab, Key);
-db_next_key(disc_only_copies, Tab, Key) -> dets:next(Tab, Key).
+db_next_key(disc_only_copies, Tab, Key) -> dets:next(Tab, Key);
+db_next_key({ext, Alias, Mod}, Tab, Key) ->
+    Mod:next(Alias, Tab, Key).
 
 db_last(Tab) ->
     db_last(val({Tab, storage_type}), Tab).
 db_last(ram_copies, Tab) -> ?ets_last(Tab);
 db_last(disc_copies, Tab) -> ?ets_last(Tab);
-db_last(disc_only_copies, Tab) -> dets:first(Tab). %% Dets don't have order
+db_last(disc_only_copies, Tab) -> dets:first(Tab); %% Dets don't have order
+db_last({ext, Alias, Mod}, Tab) ->
+    Mod:last(Alias, Tab).
 
 db_prev_key(Tab, Key) ->
     db_prev_key(val({Tab, storage_type}), Tab, Key).
 db_prev_key(ram_copies, Tab, Key) -> ?ets_prev(Tab, Key);
 db_prev_key(disc_copies, Tab, Key) -> ?ets_prev(Tab, Key);
-db_prev_key(disc_only_copies, Tab, Key) -> dets:next(Tab, Key). %% Dets don't have order
+db_prev_key(disc_only_copies, Tab, Key) -> dets:next(Tab, Key); %% Dets don't have order
+db_prev_key({ext, Alias, Mod}, Tab, Key) ->
+    Mod:prev(Alias, Tab, Key).
 
 db_slot(Tab, Pos) ->
     db_slot(val({Tab, storage_type}), Tab, Pos).
 db_slot(ram_copies, Tab, Pos) -> ?ets_slot(Tab, Pos);
 db_slot(disc_copies, Tab, Pos) -> ?ets_slot(Tab, Pos);
-db_slot(disc_only_copies, Tab, Pos) -> dets:slot(Tab, Pos).
+db_slot(disc_only_copies, Tab, Pos) -> dets:slot(Tab, Pos);
+db_slot({ext, Alias, Mod}, Tab, Pos) ->
+    Mod:slot(Alias, Tab, Pos).
 
 db_update_counter(Tab, C, Val) ->
     db_update_counter(val({Tab, storage_type}), Tab, C, Val).
@@ -1190,13 +1302,16 @@ db_update_counter(ram_copies, Tab, C, Val) ->
 db_update_counter(disc_copies, Tab, C, Val) ->
     ?ets_update_counter(Tab, C, Val);
 db_update_counter(disc_only_copies, Tab, C, Val) ->
-    dets:update_counter(Tab, C, Val).
+    dets:update_counter(Tab, C, Val);
+db_update_counter({ext, Alias, Mod}, Tab, C, Val) ->
+    Mod:update_counter(Alias, Tab, C, Val).
 
 db_erase_tab(Tab) ->
     db_erase_tab(val({Tab, storage_type}), Tab).
 db_erase_tab(ram_copies, Tab) -> ?ets_delete_table(Tab);
 db_erase_tab(disc_copies, Tab) -> ?ets_delete_table(Tab);
-db_erase_tab(disc_only_copies, _Tab) -> ignore.
+db_erase_tab(disc_only_copies, _Tab) -> ignore;
+db_erase_tab({ext, _Alias, _Mod}, _Tab) -> ignore.
 
 %% assuming that Tab is a valid ets-table
 dets_to_ets(Tabname, Tab, File, Type, Rep, Lock) ->
@@ -1205,7 +1320,7 @@ dets_to_ets(Tabname, Tab, File, Type, Rep, Lock) ->
 			{keypos, 2}, {repair, Rep}]) of
 	{ok, Tabname} ->
 	    Res = dets:to_ets(Tabname, Tab),
-	    Close(Tabname),
+	    ok = Close(Tabname),
 	    trav_ret(Res, Tab);
 	Other ->
 	    Other
@@ -1255,7 +1370,7 @@ dets_sync_open(Tab, Args) ->
     end.
 
 dets_sync_close(Tab) ->
-    catch dets:close(Tab),
+    ?SAFE(dets:close(Tab)),
     unlock_table(Tab),
     ok.
 
@@ -1291,7 +1406,7 @@ readable_indecies(Tab) ->
 
 scratch_debug_fun() ->
     dbg_out("scratch_debug_fun(): ~p~n", [?DEBUG_TAB]),
-    (catch ?ets_delete_table(?DEBUG_TAB)),
+    ?SAFE(?ets_delete_table(?DEBUG_TAB)),
     ?ets_new_table(?DEBUG_TAB, [set, public, named_table, {keypos, 2}]).
 
 activate_debug_fun(FunId, Fun, InitialContext, File, Line) ->
@@ -1304,43 +1419,45 @@ activate_debug_fun(FunId, Fun, InitialContext, File, Line) ->
     update_debug_info(Info).
 
 update_debug_info(Info) ->
-    case catch ?ets_insert(?DEBUG_TAB, Info) of
-	{'EXIT', _} ->
+    try ?ets_insert(?DEBUG_TAB, Info),
+	 ok
+    catch error:_ ->
 	    scratch_debug_fun(),
-	    ?ets_insert(?DEBUG_TAB, Info);
-	_ ->
-	    ok
+	    ?ets_insert(?DEBUG_TAB, Info)
     end,
     dbg_out("update_debug_info(~p)~n", [Info]),
     ok.
 
 deactivate_debug_fun(FunId, _File, _Line) ->
-    catch ?ets_delete(?DEBUG_TAB, FunId),
+    ?SAFE(?ets_delete(?DEBUG_TAB, FunId)),
     ok.
 
 eval_debug_fun(FunId, EvalContext, EvalFile, EvalLine) ->
-    case catch ?ets_lookup(?DEBUG_TAB, FunId) of
-	[] ->
-	    ok;
-	[Info] ->
-	    OldContext = Info#debug_info.context,
-	    dbg_out("~s(~p): ~w "
-		    "activated in ~s(~p)~n  "
-		    "eval_debug_fun(~w, ~w)~n",
-		    [filename:basename(EvalFile), EvalLine, Info#debug_info.id,
-		     filename:basename(Info#debug_info.file), Info#debug_info.line,
-		     OldContext, EvalContext]),
-	    Fun = Info#debug_info.function,
-	    NewContext = Fun(OldContext, EvalContext),
-	    
-	    case catch ?ets_lookup(?DEBUG_TAB, FunId) of
-		[Info] when NewContext /= OldContext ->
-		    NewInfo = Info#debug_info{context = NewContext},
-		    update_debug_info(NewInfo);
-		_ ->
-		    ok
-	    end;
-	{'EXIT', _} -> ok    
+    try 
+	case ?ets_lookup(?DEBUG_TAB, FunId) of
+	    [] ->
+		ok;
+	    [Info] ->
+		OldContext = Info#debug_info.context,
+		dbg_out("~s(~p): ~w "
+			"activated in ~s(~p)~n  "
+			"eval_debug_fun(~w, ~w)~n",
+			[filename:basename(EvalFile), EvalLine, Info#debug_info.id,
+			 filename:basename(Info#debug_info.file), Info#debug_info.line,
+			 OldContext, EvalContext]),
+		Fun = Info#debug_info.function,
+		NewContext = Fun(OldContext, EvalContext),
+
+		case ?ets_lookup(?DEBUG_TAB, FunId) of
+		    [Info] when NewContext /= OldContext ->
+			NewInfo = Info#debug_info{context = NewContext},
+			update_debug_info(NewInfo);
+		    _ ->
+			ok
+		end
+	end
+    catch error ->
+	    ok
     end.
 	
 -ifdef(debug).
diff --git a/lib/mnesia/src/mnesia_loader.erl b/lib/mnesia/src/mnesia_loader.erl
index 4afbea1cc2..71e5829c87 100644
--- a/lib/mnesia/src/mnesia_loader.erl
+++ b/lib/mnesia/src/mnesia_loader.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1998-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -35,7 +36,7 @@
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason);
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
 	Value -> Value
     end.
 
@@ -69,9 +70,10 @@ do_get_disc_copy2(Tab, Reason, Storage, Type) when Storage == disc_copies ->
 	    ignore;
 	_ ->
 	    mnesia_monitor:mktab(Tab, Args),
-	    Count = mnesia_log:dcd2ets(Tab, Repair),
-	    case ets:info(Tab, size) of
-		X when X < Count * 4 ->
+	    _Count = mnesia_log:dcd2ets(Tab, Repair),
+	    case mnesia_monitor:get_env(dump_disc_copies_at_startup)
+		andalso mnesia_dumper:needs_dump_ets(Tab) of
+		true ->
 		    ok = mnesia_log:ets2dcd(Tab);
 		_ ->
 		    ignore
@@ -145,6 +147,19 @@ do_get_disc_copy2(Tab, Reason, Storage, Type) when Storage == disc_only_copies -
 		{error, Error} ->
 		    {not_loaded, {"Failed to create dets table", Error}}
 	    end
+    end;
+
+do_get_disc_copy2(Tab, Reason, Storage = {ext, Alias, Mod}, _Type) ->
+    Cs = val({Tab, cstruct}),
+    case mnesia_monitor:unsafe_create_external(Tab, Alias, Mod, Cs) of
+	ok ->
+	    ok = ext_load_table(Mod, Alias, Tab, Reason),
+	    mnesia_index:init_index(Tab, Storage),
+	    set({Tab, load_node}, node()),
+	    set({Tab, load_reason}, Reason),
+	    {loaded, ok};
+	Other ->
+	    {not_loaded, Other}
     end.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -178,8 +193,7 @@ do_get_disc_copy2(Tab, Reason, Storage, Type) when Storage == disc_only_copies -
 -define(MAX_RAM_TRANSFERS, (?MAX_RAM_FILE_SIZE div ?MAX_TRANSFER_SIZE) + 1).
 -define(MAX_NOPACKETS, 20).
 
-net_load_table(Tab, Reason, Ns, Cs)
-        when Reason == {dumper,add_table_copy} ->
+net_load_table(Tab, {dumper,{add_table_copy, _}}=Reason, Ns, Cs) ->
     try_net_load_table(Tab, Reason, Ns, Cs);
 net_load_table(Tab, Reason, Ns, _Cs) ->
     try_net_load_table(Tab, Reason, Ns, val({Tab, cstruct})).
@@ -231,7 +245,8 @@ do_snmpify(Tab, Us, Storage) ->
     set({Tab, {index, snmp}}, Snmp).
 
 %% Start the recieiver
-init_receiver(Node, Tab, Storage, Cs, Reas={dumper,add_table_copy}) ->
+init_receiver(Node, Tab, Storage, Cs, Reas={dumper,{add_table_copy, Tid}}) ->
+    rpc:call(Node, mnesia_lib, set, [{?MODULE, active_trans}, Tid]),
     case start_remote_sender(Node, Tab, Storage) of
 	{SenderPid, TabSize, DetsData} ->
 	    start_receiver(Tab,Storage,Cs,SenderPid,TabSize,DetsData,Reas);
@@ -257,7 +272,7 @@ init_receiver(Node, Tab,Storage,Cs,Reason) ->
 			true = lists:member(Node, Active),
 			{SenderPid, TabSize, DetsData} =
 			    start_remote_sender(Node,Tab,Storage),
-			Init = table_init_fun(SenderPid),
+			Init = table_init_fun(SenderPid, Storage),
 			Args = [self(),Tab,Storage,Cs,SenderPid,
 				TabSize,DetsData,Init],
 			Pid = spawn_link(?MODULE, spawned_receiver, Args),
@@ -287,7 +302,12 @@ start_remote_sender(Node,Tab,Storage) ->
     mnesia_controller:start_remote_sender(Node, Tab, self(), Storage),
     put(mnesia_table_sender_node, {Tab, Node}),
     receive
-	{SenderPid, {first, TabSize}} ->
+	{SenderPid, {first, _} = Msg}
+	  when is_pid(SenderPid), element(1, Storage) == ext ->
+	    {ext, Alias, Mod} = Storage,
+	    {Sz, Data} = Mod:receiver_first_message(SenderPid, Msg, Alias, Tab),
+	    {SenderPid, Sz, Data};
+	{SenderPid, {first, TabSize}} =_M1 ->
 	    {SenderPid, TabSize, false};
 	{SenderPid, {first, TabSize, DetsData}} ->
 	    {SenderPid, TabSize, DetsData};
@@ -297,16 +317,18 @@ start_remote_sender(Node,Tab,Storage) ->
 	    down(Tab, Storage)
     end.
 
-table_init_fun(SenderPid) ->
+table_init_fun(SenderPid, Storage) ->
     fun(read) ->
 	    Receiver = self(),
 	    SenderPid ! {Receiver, more},
-	    get_data(SenderPid, Receiver)
+	    get_data(SenderPid, Receiver, Storage);
+       (close) ->
+	    ok
     end.
 
 %% Add_table_copy get's it's own locks.
-start_receiver(Tab,Storage,Cs,SenderPid,TabSize,DetsData,{dumper,add_table_copy}) ->
-    Init = table_init_fun(SenderPid),
+start_receiver(Tab,Storage,Cs,SenderPid,TabSize,DetsData,{dumper,{add_table_copy,_}}) ->
+    Init = table_init_fun(SenderPid, Storage),
     case do_init_table(Tab,Storage,Cs,SenderPid,TabSize,DetsData,self(), Init) of
 	Err = {error, _} ->
 	    SenderPid ! {copier_done, node()},
@@ -330,7 +352,7 @@ wait_on_load_complete(Pid) ->
 	{Pid, Res} ->
 	    Res;
 	{'EXIT', Pid, Reason} ->
-	    exit(Reason);
+	    error(Reason);
 	Else ->
 	    Pid ! Else,
 	    wait_on_load_complete(Pid)
@@ -389,7 +411,15 @@ create_table(Tab, TabSize, Storage, Cs) ->
 		    {Storage, Tab};
 		Else ->
 		    Else
-	    end
+	    end;
+        element(1, Storage) == ext ->
+            {_, Alias, Mod} = Storage,
+            case mnesia_monitor:unsafe_create_external(Tab, Alias, Mod, Cs) of
+                ok ->
+                    {Storage, Tab};
+                Else ->
+                    Else
+            end
     end.
 
 tab_receiver(Node, Tab, Storage, Cs, OrigTabRec) ->
@@ -407,21 +437,25 @@ tab_receiver(Node, Tab, Storage, Cs, OrigTabRec) ->
 	    tab_receiver(Node, Tab, Storage, Cs, OrigTabRec)
     end.
 
-make_table_fun(Pid, TabRec) ->
+make_table_fun(Pid, TabRec, Storage) ->
     fun(close) ->
 	    ok;
+       ({read, Msg}) ->
+	    Pid ! {TabRec, Msg},
+	    get_data(Pid, TabRec, Storage);
        (read) ->
-	    get_data(Pid, TabRec)
+	    get_data(Pid, TabRec, Storage)
     end.
 
-get_data(Pid, TabRec) ->
+get_data(Pid, TabRec, Storage) ->
     receive
 	{Pid, {more_z, CompressedRecs}} when is_binary(CompressedRecs) ->
-	    Pid ! {TabRec, more},
-	    {zlib_uncompress(CompressedRecs), make_table_fun(Pid,TabRec)};
+	    maybe_reply(Pid, {TabRec, more}, Storage),
+	    {zlib_uncompress(CompressedRecs),
+	     make_table_fun(Pid, TabRec, Storage)};
 	{Pid, {more, Recs}} ->
-	    Pid ! {TabRec, more},
-	    {Recs, make_table_fun(Pid,TabRec)};
+	    maybe_reply(Pid, {TabRec, more}, Storage),
+	    {Recs, make_table_fun(Pid, TabRec, Storage)};
 	{Pid, no_more} ->
 	    end_of_input;
 	{copier_done, Node} ->
@@ -429,29 +463,64 @@ get_data(Pid, TabRec) ->
 		Node ->
 		    {copier_done, Node};
 		_ ->
-		    get_data(Pid, TabRec)
+		    get_data(Pid, TabRec, Storage)
 	    end;
 	{'EXIT', Pid, Reason} ->
 	    handle_exit(Pid, Reason),
-	    get_data(Pid, TabRec)
+	    get_data(Pid, TabRec, Storage)
     end.
 
+maybe_reply(_, _, {ext, _, _}) ->
+    ignore;
+maybe_reply(Pid, Msg, _) ->
+    Pid ! Msg.
+
+ext_init_table(Alias, Mod, Tab, Fun, State, Sender) ->
+    ok = ext_load_table(Mod, Alias, Tab, {net_load, node(Sender)}),
+    ext_init_table(read, Alias, Mod, Tab, Fun, State, Sender).
+
+ext_load_table(Mod, Alias, Tab, Reason) ->
+    CS = val({Tab, cstruct}),
+    Mod:load_table(Alias, Tab, Reason, mnesia_schema:cs2list(CS)).
+
+
+ext_init_table(Action, Alias, Mod, Tab, Fun, State, Sender) ->
+    case Fun(Action) of
+	{copier_done, Node} ->
+	    verbose("Receiver of table ~p crashed on ~p (more)~n", [Tab, Node]),
+	    down(Tab, {ext,Alias,Mod});
+	{Data, NewFun} ->
+	    case Mod:receive_data(Data, Alias, Tab, Sender, State) of
+		{more, NewState} ->
+		    ext_init_table({read, more}, Alias, Mod,
+				   Tab, NewFun, NewState, Sender);
+		{{more,Msg}, NewState} ->
+		    ext_init_table({read, Msg}, Alias, Mod,
+				   Tab, NewFun, NewState, Sender)
+	    end;
+	end_of_input ->
+	    Mod:receive_done(Alias, Tab, Sender, State),
+	    ok = Fun(close)
+    end.
+
+init_table(Tab, {ext,Alias,Mod}, Fun, State, Sender) ->
+    ext_init_table(Alias, Mod, Tab, Fun, State, Sender);
 init_table(Tab, disc_only_copies, Fun, DetsInfo,Sender) ->
     ErtsVer = erlang:system_info(version),
     case DetsInfo of
 	{ErtsVer, DetsData}  ->
-	    Res = (catch dets:is_compatible_bchunk_format(Tab, DetsData)),
-	    case Res of
-		{'EXIT',{undef,[{dets,_,_,_}|_]}} ->
-		    Sender ! {self(), {old_protocol, Tab}},
-		    dets:init_table(Tab, Fun);  %% Old dets version
-		{'EXIT', What} ->
-		    exit(What);
+	    try dets:is_compatible_bchunk_format(Tab, DetsData) of
 		false ->
 		    Sender ! {self(), {old_protocol, Tab}},
 		    dets:init_table(Tab, Fun);  %% Old dets version
 		true ->
 		    dets:init_table(Tab, Fun, [{format, bchunk}])
+	    catch
+		error:{undef,[{dets,_,_,_}|_]} ->
+		    Sender ! {self(), {old_protocol, Tab}},
+		    dets:init_table(Tab, Fun);  %% Old dets version
+		error:What ->
+		    What
 	    end;
 	Old when Old /= false ->
 	    Sender ! {self(), {old_protocol, Tab}},
@@ -460,10 +529,10 @@ init_table(Tab, disc_only_copies, Fun, DetsInfo,Sender) ->
 	    dets:init_table(Tab, Fun)
     end;
 init_table(Tab, _, Fun, _DetsInfo,_) ->
-    case catch ets:init_table(Tab, Fun) of
-	true ->
-	    ok;
-	{'EXIT', Else} -> Else
+    try
+	true = ets:init_table(Tab, Fun),
+	ok
+    catch _:Else -> {Else, erlang:get_stacktrace()}
     end.
 
 
@@ -565,18 +634,24 @@ handle_last({ram_copies, Tab}, _Type, DatBin) ->
 	    ok;
 	false ->
 	    ok
-    end.
+    end;
+
+handle_last(_Storage, _Type, nobin) ->
+    ok.
 
 down(Tab, Storage) ->
     case Storage of
 	ram_copies ->
-	    catch ?ets_delete_table(Tab);
+	    ?SAFE(?ets_delete_table(Tab));
 	disc_copies ->
-	    catch ?ets_delete_table(Tab);
+	    ?SAFE(?ets_delete_table(Tab));
 	disc_only_copies ->
 	    TmpFile = mnesia_lib:tab2tmp(Tab),
 	    mnesia_lib:dets_sync_close(Tab),
-	    file:delete(TmpFile)
+	    file:delete(TmpFile);
+        {ext, Alias, Mod} ->
+	    catch Mod:close_table(Alias, Tab),
+            catch Mod:delete_table(Alias, Tab)
     end,
     mnesia_checkpoint:tm_del_copy(Tab, node()),
     mnesia_controller:sync_del_table_copy_whereabouts(Tab, node()),
@@ -601,21 +676,35 @@ db_erase({ram_copies, Tab}, Key) ->
 db_erase({disc_copies, Tab}, Key) ->
     true = ?ets_delete(Tab, Key);
 db_erase({disc_only_copies, Tab}, Key) ->
-    ok = dets:delete(Tab, Key).
+    ok = dets:delete(Tab, Key);
+db_erase({{ext, Alias, Mod}, Tab}, Key) ->
+    ok = Mod:delete(Alias, Tab, Key).
 
 db_match_erase({ram_copies, Tab} , Pat) ->
     true = ?ets_match_delete(Tab, Pat);
 db_match_erase({disc_copies, Tab} , Pat) ->
     true = ?ets_match_delete(Tab, Pat);
 db_match_erase({disc_only_copies, Tab}, Pat) ->
-    ok = dets:match_delete(Tab, Pat).
+    ok = dets:match_delete(Tab, Pat);
+db_match_erase({{ext, Alias, Mod}, Tab}, Pat) ->
+    % "ets style" is to return true
+    % "dets style" is to return N | { error, Reason }
+    %   or sometimes ok (?)
+    % be nice and accept both
+    case Mod:match_delete(Alias, Tab, Pat) of
+      N when is_integer (N) -> ok;
+      true -> ok;
+      ok -> ok
+    end.
 
 db_put({ram_copies, Tab}, Val) ->
     true = ?ets_insert(Tab, Val);
 db_put({disc_copies, Tab}, Val) ->
     true = ?ets_insert(Tab, Val);
 db_put({disc_only_copies, Tab}, Val) ->
-    ok = dets:insert(Tab, Val).
+    ok = dets:insert(Tab, Val);
+db_put({{ext, Alias, Mod}, Tab}, Val) ->
+    ok = Mod:insert(Alias, Tab, Val).
 
 %% This code executes at the remote site where the data is
 %% executes in a special copier process.
@@ -634,65 +723,88 @@ send_table(Pid, Tab, RemoteS) ->
 	unknown ->
 	    {error, {no_exists, Tab}};
 	Storage ->
-	    %% Send first
-	    TabSize = mnesia:table_info(Tab, size),
-	    KeysPerTransfer = calc_nokeys(Storage, Tab),
-	    ChunkData = dets:info(Tab, bchunk_format),
-
-	    UseDetsChunk =
-		Storage == RemoteS andalso
-		Storage == disc_only_copies andalso
-		ChunkData /= undefined,
-	    if
-		UseDetsChunk == true ->
-		    DetsInfo = erlang:system_info(version),
-		    Pid ! {self(), {first, TabSize, {DetsInfo, ChunkData}}};
-		true  ->
-		    Pid ! {self(), {first, TabSize}}
-	    end,
+	    do_send_table(Pid, Tab, Storage, RemoteS)
+    end.
 
-	    %% Debug info
-	    put(mnesia_table_sender, {Tab, node(Pid), Pid}),
-	    {Init, Chunk} = reader_funcs(UseDetsChunk, Tab, Storage, KeysPerTransfer),
-
-	    SendIt = fun() ->
-			     prepare_copy(Pid, Tab, Storage),
-			     send_more(Pid, 1, Chunk, Init(), Tab),
-			     finish_copy(Pid, Tab, Storage, RemoteS)
-		     end,
-
-	    case catch SendIt() of
-		receiver_died ->
-		    cleanup_tab_copier(Pid, Storage, Tab),
-		    unlink(whereis(mnesia_tm)),
-		    ok;
-		{_, receiver_died} ->
-		    unlink(whereis(mnesia_tm)),
-		    ok;
-		{atomic, no_more} ->
-		    unlink(whereis(mnesia_tm)),
-		    ok;
-		Reason ->
-		    cleanup_tab_copier(Pid, Storage, Tab),
-		    unlink(whereis(mnesia_tm)),
-		    {error, Reason}
-	    end
+do_send_table(Pid, Tab, Storage, RemoteS) ->
+    {Init, Chunk} =
+	case Storage of
+	    {ext, Alias, Mod} ->
+		case Mod:sender_init(Alias, Tab, RemoteS, Pid) of
+		    {standard, I, C} ->
+			Pid ! {self(), {first, Mod:info(Alias, Tab, size)}},
+			{I, C};
+		    {_, _} = Res ->
+			Res
+		end;
+	    Storage ->
+		%% Send first
+		TabSize = mnesia:table_info(Tab, size),
+		KeysPerTransfer = calc_nokeys(Storage, Tab),
+		ChunkData = dets:info(Tab, bchunk_format),
+
+		UseDetsChunk =
+		    Storage == RemoteS andalso
+		    Storage == disc_only_copies andalso
+		    ChunkData /= undefined,
+		if
+		    UseDetsChunk == true ->
+			DetsInfo = erlang:system_info(version),
+			Pid ! {self(), {first, TabSize, {DetsInfo, ChunkData}}};
+		    true  ->
+			Pid ! {self(), {first, TabSize}}
+		end,
+		{_I, _C} =
+		    reader_funcs(UseDetsChunk, Tab, Storage, KeysPerTransfer)
+	end,
+    %% Debug info
+    put(mnesia_table_sender, {Tab, node(Pid), Pid}),
+
+    SendIt = fun() ->
+		     NeedLock = need_lock(Tab),
+		     {atomic, ok} = prepare_copy(Pid, Tab, Storage, NeedLock),
+		     send_more(Pid, 1, Chunk, Init(), Tab, Storage),
+		     finish_copy(Pid, Tab, Storage, RemoteS, NeedLock)
+	     end,
+
+    try SendIt() of
+        {_, receiver_died} -> ok;
+        {atomic, no_more} ->  ok
+    catch
+        throw:receiver_died ->
+            cleanup_tab_copier(Pid, Storage, Tab),
+            ok;
+        error:Reason -> %% Prepare failed
+            cleanup_tab_copier(Pid, Storage, Tab),
+            {error, {tab_copier, Tab, {Reason, erlang:get_stacktrace()}}}
+    after
+        unlink(whereis(mnesia_tm))
     end.
 
-prepare_copy(Pid, Tab, Storage) ->
+prepare_copy(Pid, Tab, Storage, NeedLock) ->
     Trans =
 	fun() ->
-		mnesia:lock_table(Tab, load),
+		NeedLock andalso mnesia:lock_table(Tab, load),
 		mnesia_subscr:subscribe(Pid, {table, Tab}),
 		update_where_to_write(Tab, node(Pid)),
 		mnesia_lib:db_fixtable(Storage, Tab, true),
 		ok
 	end,
-    case mnesia:transaction(Trans) of
-	{atomic, ok} ->
-	    ok;
-	{aborted, Reason} ->
-	    exit({tab_copier_prepare, Tab, Reason})
+    mnesia:transaction(Trans).
+
+
+need_lock(Tab) ->
+    case ?catch_val({?MODULE, active_trans}) of
+	#tid{} = Tid ->
+	    %% move_table_copy grabs it's own table-lock
+	    %% do not deadlock with it
+	    mnesia_lib:unset({?MODULE, active_trans}),
+	    case mnesia_locker:get_held_locks(Tab) of
+		[{write, Tid}|_] -> false;
+		_Locks -> true
+	    end;
+	_ ->
+	    true
     end.
 
 update_where_to_write(Tab, Node) ->
@@ -716,20 +828,32 @@ update_where_to_write([H|T], Tab, AddNode) ->
 	     [{update_where_to_write, [add, Tab, AddNode], self()}]),
     update_where_to_write(T, Tab, AddNode).
 
-send_more(Pid, N, Chunk, DataState, Tab) ->
+send_more(Pid, N, Chunk, DataState, Tab, Storage) ->
     receive
 	{NewPid, more} ->
 	    case send_packet(N - 1, NewPid, Chunk, DataState) of
 		New when is_integer(New) ->
 		    New - 1;
 		NewData ->
-		    send_more(NewPid, ?MAX_NOPACKETS, Chunk, NewData, Tab)
+		    send_more(NewPid, ?MAX_NOPACKETS, Chunk, NewData,
+			      Tab, Storage)
+	    end;
+	{NewPid, {more, Msg}} when element(1, Storage) == ext ->
+	    {ext, Alias, Mod} = Storage,
+	    {NewChunk, NewState} =
+		Mod:sender_handle_info(Msg, Alias, Tab, NewPid, DataState),
+	    case send_packet(N - 1, NewPid, NewChunk, NewState) of
+		New when is_integer(New) ->
+		    New -1;
+		NewData ->
+		    send_more(NewPid, N, NewChunk, NewData, Tab,
+			      Storage)
 	    end;
 	{_NewPid, {old_protocol, Tab}} ->
 	    Storage =  val({Tab, storage_type}),
 	    {Init, NewChunk} =
 		reader_funcs(false, Tab, Storage, calc_nokeys(Storage, Tab)),
-	    send_more(Pid, 1, NewChunk, Init(), Tab);
+	    send_more(Pid, 1, NewChunk, Init(), Tab, Storage);
 
 	{copier_done, Node} when Node == node(Pid)->
 	    verbose("Receiver of table ~p crashed on ~p (more)~n", [Tab, Node]),
@@ -789,12 +913,12 @@ send_packet(N, Pid, Chunk, {Recs, Cont}) when N < ?MAX_NOPACKETS ->
 send_packet(_N, _Pid, _Chunk, DataState) ->
     DataState.
 
-finish_copy(Pid, Tab, Storage, RemoteS) ->
+finish_copy(Pid, Tab, Storage, RemoteS, NeedLock) ->
     RecNode = node(Pid),
     DatBin = dat2bin(Tab, Storage, RemoteS),
     Trans =
 	fun() ->
-		mnesia:read_lock_table(Tab),
+		NeedLock andalso mnesia:read_lock_table(Tab),
 		A = val({Tab, access_mode}),
 		mnesia_controller:sync_and_block_table_whereabouts(Tab, RecNode, RemoteS, A),
 		cleanup_tab_copier(Pid, Storage, Tab),
@@ -826,6 +950,6 @@ dat2bin(_Tab, _LocalS, _RemoteS) ->
     nobin.
 
 handle_exit(Pid, Reason) when node(Pid) == node() ->
-    exit(Reason);
+    error(Reason);
 handle_exit(_Pid, _Reason) ->  %% Not from our node, this will be handled by
     ignore.                  %% mnesia_down soon.
diff --git a/lib/mnesia/src/mnesia_locker.erl b/lib/mnesia/src/mnesia_locker.erl
index 14011003d3..59fd89059f 100644
--- a/lib/mnesia/src/mnesia_locker.erl
+++ b/lib/mnesia/src/mnesia_locker.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -21,13 +22,13 @@
 -module(mnesia_locker).
 
 -export([
-	 get_held_locks/0,
+	 get_held_locks/0, get_held_locks/1,
 	 get_lock_queue/0,
 	 global_lock/5,
 	 ixrlock/5,
 	 init/1,
-	 mnesia_down/2,
 	 release_tid/1,
+	 mnesia_down/2,
 	 async_release_tid/2,
 	 send_release_tid/2,
 	 receive_release_tid_acc/2,
@@ -84,7 +85,7 @@ init(Parent) ->
     register(?MODULE, self()),
     process_flag(trap_exit, true),
     ?ets_new_table(mnesia_held_locks, [ordered_set, private, named_table]),
-    ?ets_new_table(mnesia_tid_locks, [bag, private, named_table]),
+    ?ets_new_table(mnesia_tid_locks, [ordered_set, private, named_table]),
     ?ets_new_table(mnesia_sticky_locks, [set, private, named_table]),
     ?ets_new_table(mnesia_lock_queue, [bag, private, named_table, {keypos, 2}]),
 
@@ -98,12 +99,13 @@ init(Parent) ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', _ReASoN_} -> mnesia_lib:other_val(Var, _ReASoN_);
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
 	_VaLuE_ -> _VaLuE_
     end.
 
 reply(From, R) ->
-    From ! {?MODULE, node(), R}.
+    From ! {?MODULE, node(), R},
+    true. %% Quiets dialyzer
 
 l_request(Node, X, Store) ->
     {?MODULE, Node} ! {self(), X},
@@ -130,13 +132,29 @@ send_release_tid(Nodes, Tid) ->
 receive_release_tid_acc([Node | Nodes], Tid) ->
     receive
 	{?MODULE, Node, {tid_released, Tid}} ->
-	    receive_release_tid_acc(Nodes, Tid);
-	{mnesia_down, Node} ->
 	    receive_release_tid_acc(Nodes, Tid)
+    after 0 ->
+	    receive
+		{?MODULE, Node, {tid_released, Tid}} ->
+		    receive_release_tid_acc(Nodes, Tid);
+		{mnesia_down, Node} ->
+		    receive_release_tid_acc(Nodes, Tid)
+	    end
     end;
 receive_release_tid_acc([], _Tid) ->
     ok.
 
+mnesia_down(Node, Pending) ->
+    case whereis(?MODULE) of
+	undefined -> {error, node_not_running};
+	Pid ->
+	    Ref = make_ref(),
+	    Pid ! {{self(), Ref}, {release_remote_non_pending, Node, Pending}},
+	    receive   %% No need to wait for anything else if process dies we die soon
+		{Ref,ok} -> ok
+	    end
+    end.
+
 loop(State) ->
     receive
 	{From, {write, Tid, Oid}} ->
@@ -213,9 +231,14 @@ loop(State) ->
 	    reply(From, {tid_released, Tid}),
 	    loop(State);
 
-	{release_remote_non_pending, Node, Pending} ->
+	{{From, Ref},{release_remote_non_pending, Node, Pending}} ->
 	    release_remote_non_pending(Node, Pending),
-	    mnesia_monitor:mnesia_down(?MODULE, Node),
+	    From ! {Ref, ok},
+	    loop(State);
+
+	{From, {is_locked, Oid}} ->
+	    Held = ?ets_lookup(mnesia_held_locks, Oid),
+	    reply(From, Held),
 	    loop(State);
 
 	{'EXIT', Pid, _} when Pid == State#state.supervisor ->
@@ -236,13 +259,13 @@ loop(State) ->
     end.
 
 set_lock(Tid, Oid, Op, []) ->
-    ?ets_insert(mnesia_tid_locks, {Tid, Oid, Op}),
+    ?ets_insert(mnesia_tid_locks, {{Tid, Oid, Op}}),
     ?ets_insert(mnesia_held_locks, {Oid, Op, [{Op, Tid}]});
 set_lock(Tid, Oid, read, [{Oid, Prev, Items}]) ->
-    ?ets_insert(mnesia_tid_locks, {Tid, Oid, read}),
+    ?ets_insert(mnesia_tid_locks, {{Tid, Oid, read}}),
     ?ets_insert(mnesia_held_locks, {Oid, Prev, [{read, Tid}|Items]});
 set_lock(Tid, Oid, write, [{Oid, _Prev, Items}]) ->
-    ?ets_insert(mnesia_tid_locks, {Tid, Oid, write}),
+    ?ets_insert(mnesia_tid_locks, {{Tid, Oid, write}}),
     ?ets_insert(mnesia_held_locks, {Oid, write, [{write, Tid}|Items]});
 set_lock(Tid, Oid, Op, undefined) ->
     set_lock(Tid, Oid, Op, ?ets_lookup(mnesia_held_locks, Oid)).
@@ -258,7 +281,8 @@ try_sticky_lock(Tid, Op, Pid, {Tab, _} = Oid) ->
 	    try_lock(Tid, Op, Pid, Oid);
 	[{_,N}] ->
 	    Req = {Pid, {Op, Tid, Oid}},
-	    Pid ! {?MODULE, node(), {switch, N, Req}}
+	    Pid ! {?MODULE, node(), {switch, N, Req}},
+	    true
     end.
 
 try_lock(Tid, read_write, Pid, Oid) ->
@@ -281,7 +305,7 @@ try_lock(Tid, Op, SimpleOp, Lock, Pid, Oid) ->
 	    ?ets_insert(mnesia_lock_queue,
 			#queue{oid = Oid, tid = Tid, op = Op,
 			       pid = Pid, lucky = Lucky}),
-	    ?ets_insert(mnesia_tid_locks, {Tid, Oid, {queued, Op}})
+	    ?ets_insert(mnesia_tid_locks, {{Tid, Oid, {queued, Op}}})
     end.
 
 grant_lock(Tid, read, Lock, Oid = {Tab, Key}, Default)
@@ -480,7 +504,7 @@ set_read_lock_on_all_keys(Tid, From, Tab, IxKey, Pos) ->
 	    ?ets_insert(mnesia_lock_queue,
 			#queue{oid = Oid, tid = Tid, op = Op,
 			       pid = From, lucky = Lucky}),
-	    ?ets_insert(mnesia_tid_locks, {Tid, Oid, {queued, Op}})
+	    ?ets_insert(mnesia_tid_locks, {{Tid, Oid, {queued, Op}}})
     end.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -496,7 +520,8 @@ release_remote_non_pending(Node, Pending) ->
     %% running at the failed node and also simply remove all
     %% queue'd requests back to the failed node
 
-    AllTids = ?ets_match(mnesia_tid_locks, {'$1', '_', '_'}),
+    AllTids0 = ?ets_match(mnesia_tid_locks, {{'$1', '_', '_'}}),
+    AllTids  = lists:usort(AllTids0),
     Tids = [T || [T] <- AllTids, Node == node(T#tid.pid), not lists:member(T, Pending)],
     do_release_tids(Tids).
 
@@ -507,9 +532,10 @@ do_release_tids([]) ->
     ok.
 
 do_release_tid(Tid) ->
-    Locks = ?ets_lookup(mnesia_tid_locks, Tid),
+    Objects = ets:select(mnesia_tid_locks, [{{{Tid, '_', '_'}}, [], ['$_']}]),
+    Locks = lists:map(fun({L}) -> L end, Objects),
     ?dbg("Release ~p ~p ~n", [Tid, Locks]),
-    ?ets_delete(mnesia_tid_locks, Tid),
+    [?ets_delete(mnesia_tid_locks, L) || L <- Locks],
     release_locks(Locks),
     %% Removed queued locks which has had locks
     UniqueLocks = keyunique(lists:sort(Locks),[]),
@@ -653,19 +679,6 @@ ix_read_res(Tab,IxKey,Pos) ->
 %% ********************* end server code ********************
 %% The following code executes at the client side of a transactions
 
-mnesia_down(N, Pending) ->
-    case whereis(?MODULE) of
-	undefined ->
-	    %% Takes care of mnesia_down's in early startup
-	    mnesia_monitor:mnesia_down(?MODULE, N);
-	Pid ->
-	    %% Syncronously call needed in order to avoid
-	    %% race with mnesia_tm's coordinator processes
-	    %% that may restart and acquire new locks.
-	    %% mnesia_monitor ensures the sync.
-	    Pid ! {release_remote_non_pending, N, Pending}
-    end.
-
 %% Aquire a write lock, but do a read, used by
 %% mnesia:wread/1
 
@@ -975,8 +988,14 @@ sticky_flush(Ns=[Node | Tail], Store) ->
 flush_remaining([], _SkipNode, Res) ->
     del_debug(),
     exit(Res);
-flush_remaining([SkipNode | Tail ], SkipNode, Res) ->
-    flush_remaining(Tail, SkipNode, Res);
+flush_remaining(Ns=[SkipNode | Tail ], SkipNode, Res) ->
+    add_debug(Ns),
+    receive
+	{?MODULE, SkipNode, _} ->
+	    flush_remaining(Tail, SkipNode, Res)
+    after 0 ->
+	    flush_remaining(Tail, SkipNode, Res)
+    end;
 flush_remaining(Ns=[Node | Tail], SkipNode, Res) ->
     add_debug(Ns),
     receive
@@ -988,13 +1007,11 @@ flush_remaining(Ns=[Node | Tail], SkipNode, Res) ->
 
 opt_lookup_in_client(lookup_in_client, Oid, Lock) ->
     {Tab, Key} = Oid,
-    case catch mnesia_lib:db_get(Tab, Key) of
-	{'EXIT', _} ->
+    try mnesia_lib:db_get(Tab, Key)
+    catch error:_ ->
 	    %% Table has been deleted from this node,
 	    %% restart the transaction.
-	    #cyclic{op = read, lock = Lock, oid = Oid, lucky = nowhere};
-	Val ->
-	    Val
+	    #cyclic{op = read, lock = Lock, oid = Oid, lucky = nowhere}
     end;
 opt_lookup_in_client(Val, _Oid, _Lock) ->
     Val.
@@ -1126,11 +1143,10 @@ send_requests([], _X) ->
 
 rec_requests([Node | Nodes], Oid, Store) ->
     Res = l_req_rec(Node, Store),
-    case catch rlock_get_reply(Node, Store, Oid, Res) of
-	{'EXIT', Reason} ->
-	    flush_remaining(Nodes, Node, Reason);
-	_ ->
-	    rec_requests(Nodes, Oid, Store)
+    try rlock_get_reply(Node, Store, Oid, Res) of
+	_ -> rec_requests(Nodes, Oid, Store)
+    catch _:Reason ->
+	    flush_remaining(Nodes, Node, Reason)
     end;
 rec_requests([], _Oid, _Store) ->
     ok.
@@ -1140,6 +1156,19 @@ get_held_locks() ->
     Locks = receive {mnesia_held_locks, Ls} -> Ls after 5000 -> [] end,
     rewrite_locks(Locks, []).
 
+%% Mnesia internal usage only
+get_held_locks(Tab) when is_atom(Tab) ->
+    Oid = {Tab, ?ALL},
+    ?MODULE ! {self(), {is_locked, Oid}},
+    receive
+	{?MODULE, _Node, Locks} ->
+	    case Locks of
+		[] -> [];
+		[{Oid, _Prev, What}] -> What
+	    end
+    end.
+
+
 rewrite_locks([{Oid, _, Ls}|Locks], Acc0) ->
     Acc = rewrite_locks(Ls, Oid, Acc0),
     rewrite_locks(Locks, Acc);
diff --git a/lib/mnesia/src/mnesia_log.erl b/lib/mnesia/src/mnesia_log.erl
index 18303869ed..9536effd42 100644
--- a/lib/mnesia/src/mnesia_log.erl
+++ b/lib/mnesia/src/mnesia_log.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -200,7 +201,7 @@ log_header(Kind, Version) ->
 		log_kind=Kind,
 		mnesia_version=mnesia:system_info(version),
 		node=node(),
-		now=now()}.
+		now=erlang:timestamp()}.
 
 version() -> "4.3".
 
@@ -223,17 +224,12 @@ sappend(Log, Term) ->
     ok = disk_log:log(Log, Term).
 
 %% Write commit records to the latest_log
-log(C) when  C#commit.disc_copies == [],
-             C#commit.disc_only_copies  == [],
-             C#commit.schema_ops == [] ->
-    ignore;
 log(C) ->
-    case mnesia_monitor:use_dir() of
+    case need_log(C) andalso mnesia_monitor:use_dir() of
         true ->
 	    if
 		is_record(C, commit) ->
-		    C2 =  C#commit{ram_copies = [], snmp = []},
-		    append(latest_log, C2);
+		    append(latest_log, strip_snmp(C));
 		true ->
 		    %% Either a commit record as binary
 		    %% or some decision related info
@@ -246,17 +242,12 @@ log(C) ->
 
 %% Synced
 
-slog(C) when  C#commit.disc_copies == [],
-             C#commit.disc_only_copies  == [],
-             C#commit.schema_ops == [] ->
-    ignore;
 slog(C) ->
-    case mnesia_monitor:use_dir() of
+    case need_log(C) andalso mnesia_monitor:use_dir() of
         true ->
 	    if
 		is_record(C, commit) ->
-		    C2 =  C#commit{ram_copies = [], snmp = []},
-		    sappend(latest_log, C2);
+		    sappend(latest_log, strip_snmp(C));
 		true ->
 		    %% Either a commit record as binary
 		    %% or some decision related info
@@ -267,6 +258,13 @@ slog(C) ->
 	    ignore
     end.
 
+need_log(#commit{disc_copies=[], disc_only_copies=[], schema_ops=[], ext=Ext}) ->
+    lists:keymember(ext_copies, 1, Ext);
+need_log(_) -> true.
+
+strip_snmp(#commit{ext=[]}=CR) -> CR;
+strip_snmp(#commit{ext=Ext}=CR) ->
+    CR#commit{ext=lists:keydelete(snmp, 1, Ext)}.
 
 %% Stuff related to the file LOG
 
@@ -349,6 +347,8 @@ open_log(Name, Header, Fname, Exists, Repair, Mode) ->
 	    mnesia_lib:important("Data may be missing, log ~p repaired: Lost ~p bytes~n",
 				 [Fname, BadBytes]),
 	    Log;
+	{error, Reason = {file_error, _Fname, emfile}} ->
+	    fatal("Cannot open log file ~p: ~p~n", [Fname, Reason]);
 	{error, Reason} when Repair == true ->
 	    file:delete(Fname),
 	    mnesia_lib:important("Data may be missing, Corrupt logfile deleted: ~p, ~p ~n",
@@ -393,13 +393,15 @@ unsafe_close_log(Log) ->
 
 purge_some_logs() ->
     mnesia_monitor:unsafe_close_log(latest_log),
-    file:delete(latest_log_file()),
-    file:delete(decision_tab_file()).
+    _ = file:delete(latest_log_file()),
+    _ = file:delete(decision_tab_file()),
+    ok.
 
 purge_all_logs() ->
-    file:delete(previous_log_file()),
-    file:delete(latest_log_file()),
-    file:delete(decision_tab_file()).
+    _ = file:delete(previous_log_file()),
+    _ = file:delete(latest_log_file()),
+    _ = file:delete(decision_tab_file()),
+    ok.
 
 %% Prepare dump by renaming the open logfile if possible
 %% Returns a tuple on the following format: {Res, OpenLog}
@@ -460,7 +462,7 @@ chunk_log(Cont) ->
 chunk_log(_Log, eof) ->
     eof;
 chunk_log(Log, Cont) ->
-    case catch disk_log:chunk(Log, Cont) of
+    case disk_log:chunk(Log, Cont) of
 	{error, Reason} ->
 	    fatal("Possibly truncated ~p file: ~p~n",
 		  [Log, Reason]);
@@ -645,11 +647,11 @@ backup_checkpoint(Name, Opaque, Args) when is_list(Args) ->
     end.
 
 check_backup_args([Arg | Tail], B) ->
-    case catch check_backup_arg_type(Arg, B) of
-	{'EXIT', _Reason} ->
-	    {error, {badarg, Arg}};
+    try check_backup_arg_type(Arg, B) of
 	B2 ->
 	    check_backup_args(Tail, B2)
+    catch error:_ ->
+	    {error, {badarg, Arg}}
     end;
 
 check_backup_args([], B) ->
@@ -672,11 +674,11 @@ check_backup_arg_type(Arg, B) ->
 
 backup_master(ClientPid, B) ->
     process_flag(trap_exit, true),
-    case catch do_backup_master(B) of
-	{'EXIT', Reason} ->
-	    ClientPid ! {self(), ClientPid, {error, {'EXIT', Reason}}};
+    try do_backup_master(B) of
 	Res ->
 	    ClientPid ! {self(), ClientPid, Res}
+    catch _:Reason ->
+	    ClientPid ! {self(), ClientPid, {error, {'EXIT', Reason}}}
     end,
     unlink(ClientPid),
     exit(normal).
@@ -729,27 +731,30 @@ backup_schema(B, Tabs) ->
 safe_apply(B, write, [_, Items]) when Items == [] ->
     B;
 safe_apply(B, What, Args) ->
-    Abort = fun(R) -> abort_write(B, What, Args, R) end,
+    Abort = abort_write_fun(B, What, Args),
     receive
 	{'EXIT', Pid, R} -> Abort({'EXIT', Pid, R})
     after 0 ->
 	    Mod = B#backup_args.module,
-	    case catch apply(Mod, What, Args) of
+	    try apply(Mod, What, Args) of
 		{ok, Opaque} -> B#backup_args{opaque=Opaque};
-		{error, R} -> Abort(R);
-		R -> Abort(R)
+		{error, R} -> Abort(R)
+	    catch _:R -> Abort(R)
 	    end
     end.
 
+-spec abort_write_fun(_, _, _) -> fun((_) -> no_return()).
+abort_write_fun(B, What, Args) ->
+    fun(R) -> abort_write(B, What, Args, R) end.
+
 abort_write(B, What, Args, Reason) ->
     Mod = B#backup_args.module,
     Opaque = B#backup_args.opaque,
     dbg_out("Failed to perform backup. M=~p:F=~p:A=~p -> ~p~n",
 	    [Mod, What, Args, Reason]),
-    case catch apply(Mod, abort_write, [Opaque]) of
-	{ok, _Res} ->
-	    throw({error, Reason});
-	Other ->
+    try apply(Mod, abort_write, [Opaque]) of
+	{ok, _Res} -> throw({error, Reason})
+    catch _:Other ->
 	    error("Failed to abort backup. ~p:~p~p -> ~p~n",
 		  [Mod, abort_write, [Opaque], Other]),
 	    throw({error, Reason})
@@ -890,10 +895,8 @@ tab_receiver(Pid, B, Tab, RecName, Slot) ->
     end.
 
 rec_filter(B, schema, _RecName, Recs) ->
-    case catch mnesia_bup:refresh_cookie(Recs, B#backup_args.cookie) of
-	Recs2 when is_list(Recs2) ->
-	    Recs2;
-	{error, _Reason} ->
+    try mnesia_bup:refresh_cookie(Recs, B#backup_args.cookie)
+    catch throw:{error, _Reason} ->
 	    %% No schema table cookie
 	    Recs
     end;
@@ -1004,13 +1007,14 @@ add_recs([{{Tab, _Key}, Val, delete_object} | Rest], N) ->
     add_recs(Rest, N+1);
 add_recs([{{Tab, Key}, Val, update_counter} | Rest], N) ->
     {RecName, Incr} = Val,
-    case catch ets:update_counter(Tab, Key, Incr) of
-	CounterVal when is_integer(CounterVal) ->
-	    ok;
-	_ when Incr < 0 ->
+    try
+	CounterVal = ets:update_counter(Tab, Key, Incr),
+	true = (CounterVal >= 0)
+    catch
+	error:_ when Incr < 0 ->
 	    Zero = {RecName, Key, 0},
 	    true = ets:insert(Tab, Zero);
-	_ ->
+	error:_ ->
 	    Zero = {RecName, Key, Incr},
 	    true = ets:insert(Tab, Zero)
     end,
diff --git a/lib/mnesia/src/mnesia_monitor.erl b/lib/mnesia/src/mnesia_monitor.erl
index 7a788238fc..ab78c9b13e 100644
--- a/lib/mnesia/src/mnesia_monitor.erl
+++ b/lib/mnesia/src/mnesia_monitor.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -31,6 +32,7 @@
 	 init/0,
 	 mktab/2,
 	 unsafe_mktab/2,
+         unsafe_create_external/4,
 	 mnesia_down/2,
 	 needs_protocol_conversion/1,
 	 negotiate_protocol/1,
@@ -44,6 +46,7 @@
 	 set_env/2,
 	 start/0,
 	 start_proc/4,
+	 sync_log/1,
 	 terminate_proc/3,
 	 unsafe_close_dets/1,
 	 unsafe_close_log/1,
@@ -78,11 +81,11 @@
 
 -record(state, {supervisor, pending_negotiators = [],
 		going_down = [], tm_started = false, early_connects = [],
-		connecting, mq = []}).
+		connecting, mq = [], remote_node_status = []}).
 
--define(current_protocol_version,  {8,1}).
+-define(current_protocol_version,  {8,3}).
 
--define(previous_protocol_version, {8,0}).
+-define(previous_protocol_version, {8,2}).
 
 start() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE,
@@ -118,12 +121,17 @@ open_log(Args) ->
 reopen_log(Name, Fname, Head) ->
     unsafe_call({reopen_log, Name, Fname, Head}).
 
+sync_log(Name) ->
+    unsafe_call({sync_log, Name}).
+
 close_log(Name) ->
     unsafe_call({close_log, Name}).
 
 unsafe_close_log(Name) ->
     unsafe_call({unsafe_close_log, Name}).
 
+unsafe_create_external(Tab, Alias, Mod, Cs) ->
+    unsafe_call({unsafe_create_external, Tab, Alias, Mod, Cs}).
 
 disconnect(Node) ->
     cast({disconnect, Node}).
@@ -188,7 +196,7 @@ protocol_version() ->
 %% A sorted list of acceptable protocols the
 %% preferred protocols are first in the list
 acceptable_protocol_versions() ->
-    [protocol_version(), ?previous_protocol_version, {7,6}].
+    [protocol_version(), ?previous_protocol_version, {8,1}].
 
 needs_protocol_conversion(Node) ->
     case {?catch_val({protocol, Node}), protocol_version()} of
@@ -202,7 +210,7 @@ needs_protocol_conversion(Node) ->
 
 cast(Msg) ->
     case whereis(?MODULE) of
-	undefined -> ignore;
+	undefined -> ok;
 	Pid ->  gen_server:cast(Pid, Msg)
     end.
 
@@ -264,7 +272,7 @@ init([Parent]) ->
     set(version, Version),
     dbg_out("Version: ~p~n", [Version]),
 
-    case catch process_config_args(env()) of
+    try process_config_args(env()) of
 	ok ->
 	    mnesia_lib:set({'$$$_report', current_pos}, 0),
 	    Level = mnesia_lib:val(debug),
@@ -284,8 +292,8 @@ init([Parent]) ->
 	    set(pending_checkpoints, []),
 	    set(pending_checkpoint_pids, []),
 
-	    {ok, #state{supervisor = Parent}};
-	{'EXIT', Reason} ->
+	    {ok, #state{supervisor = Parent}}
+    catch _:Reason ->
 	    mnesia_lib:report_fatal("Bad configuration: ~p~n", [Reason]),
 	    {stop, {bad_config, Reason}}
     end.
@@ -319,25 +327,24 @@ non_empty_dir() ->
 %%----------------------------------------------------------------------
 
 handle_call({mktab, Tab, Args}, _From, State) ->
-    case catch ?ets_new_table(Tab, Args) of
-	{'EXIT', ExitReason} ->
+    try ?ets_new_table(Tab, Args) of
+	Reply ->
+	    {reply, Reply, State}
+    catch error:ExitReason ->
 	    Msg = "Cannot create ets table",
 	    Reason = {system_limit, Msg, Tab, Args, ExitReason},
 	    fatal("~p~n", [Reason]),
-	    {noreply, State};
-	Reply ->
-	    {reply, Reply, State}
+	    {noreply, State}
     end;
 
 handle_call({unsafe_mktab, Tab, Args}, _From, State) ->
-    case catch ?ets_new_table(Tab, Args) of
-	{'EXIT', ExitReason} ->
-	    {reply, {error, ExitReason}, State};
+    try ?ets_new_table(Tab, Args) of
 	Reply ->
 	    {reply, Reply, State}
+    catch error:ExitReason ->
+	    {reply, {error, ExitReason}, State}
     end;
 
-
 handle_call({open_dets, Tab, Args}, _From, State) ->
     case mnesia_lib:dets_sync_open(Tab, Args) of
 	{ok, Tab} ->
@@ -382,6 +389,9 @@ handle_call({reopen_log, Name, Fname, Head}, _From, State) ->
  	    {noreply, State}
     end;
 
+handle_call({sync_log, Name}, _From, State) ->
+    {reply, disk_log:sync(Name), State};
+
 handle_call({close_log, Name}, _From, State) ->
     case disk_log:close(Name) of
 	ok ->
@@ -395,9 +405,17 @@ handle_call({close_log, Name}, _From, State) ->
     end;
 
 handle_call({unsafe_close_log, Name}, _From, State) ->
-    disk_log:close(Name),
+    _ = disk_log:close(Name),
     {reply, ok, State};
 
+handle_call({unsafe_create_external, Tab, Alias, Mod, Cs}, _From, State) ->
+    case catch Mod:create_table(Alias, Tab, mnesia_schema:cs2list(Cs)) of
+	{'EXIT', ExitReason} ->
+	    {reply, {error, ExitReason}, State};
+	Reply ->
+	    {reply, Reply, State}
+    end;
+
 handle_call({negotiate_protocol, Mon, _Version, _Protocols}, _From, State)
   when State#state.tm_started == false ->
     State2 =  State#state{early_connects = [node(Mon) | State#state.early_connects]},
@@ -417,8 +435,6 @@ handle_call({negotiate_protocol, Mon, Version, Protocols}, From, State)
 	    case hd(Protocols) of
 		?previous_protocol_version ->
 		    accept_protocol(Mon, MyVersion, ?previous_protocol_version, From, State);
-		{7,6} ->
-		    accept_protocol(Mon, MyVersion, {7,6}, From, State);
 		_ ->
 		    verbose("Connection with ~p rejected. "
 			    "version = ~p, protocols = ~p, "
@@ -439,7 +455,7 @@ handle_call({negotiate_protocol, Nodes}, From, State) ->
     end;
 
 handle_call(init, _From, State) ->
-    net_kernel:monitor_nodes(true),
+    _ = net_kernel:monitor_nodes(true),
     EarlyNodes = State#state.early_connects,
     State2 = State#state{tm_started = true},
     {reply, EarlyNodes, State2};
@@ -482,27 +498,24 @@ handle_cast({mnesia_down, mnesia_controller, Node}, State) ->
     mnesia_tm:mnesia_down(Node),
     {noreply, State};
 
-handle_cast({mnesia_down, mnesia_tm, {Node, Pending}}, State) ->
-    mnesia_locker:mnesia_down(Node, Pending),
-    {noreply, State};
-
-handle_cast({mnesia_down, mnesia_locker, Node}, State) ->
+handle_cast({mnesia_down, mnesia_tm, Node}, State) ->
     Down = {mnesia_down, Node},
     mnesia_lib:report_system_event(Down),
     GoingDown = lists:delete(Node, State#state.going_down),
     State2 = State#state{going_down = GoingDown},
     Pending = State#state.pending_negotiators,
+    State3 = check_raise_conditon_nodeup(Node, State2),
     case lists:keysearch(Node, 1, Pending) of
 	{value, {Node, Mon, ReplyTo, Reply}} ->
 	    %% Late reply to remote monitor
 	    link(Mon),  %% link to remote Monitor
 	    gen_server:reply(ReplyTo, Reply),
 	    P2 = lists:keydelete(Node, 1,Pending),
-	    State3 = State2#state{pending_negotiators = P2},
-	    process_q(State3);
+	    State4 = State3#state{pending_negotiators = P2},
+	    process_q(State4);
 	false ->
 	    %% No pending remote monitors
-	    process_q(State2)
+	    process_q(State3)
     end;
 
 handle_cast({disconnect, Node}, State) ->
@@ -542,7 +555,7 @@ handle_info({'EXIT', Pid, fatal}, State) when node(Pid) == node() ->
     %% is in progress
     %% exit(State#state.supervisor, shutdown),
     %% It is better to kill an innocent process
-    catch exit(whereis(mnesia_locker), kill),
+    ?SAFE(exit(whereis(mnesia_locker), kill)),
     {noreply, State};
 
 handle_info(Msg = {'EXIT',Pid,_}, State) ->
@@ -568,27 +581,18 @@ handle_info({protocol_negotiated, From,Res}, State) ->
     gen_server:reply(From, Res),
     process_q(State#state{connecting = undefined});
 
-handle_info({nodeup, Node}, State) ->
-    %% Ok, we are connected to yet another Erlang node
-    %% Let's check if Mnesia is running there in order
-    %% to detect if the network has been partitioned
-    %% due to communication failure.
+handle_info({check_nodeup, Node}, State) ->
+    State2 = check_mnesia_down(Node, State),
+    {noreply, State2};
 
-    HasDown   = mnesia_recover:has_mnesia_down(Node),
-    ImRunning = mnesia_lib:is_running(),
-
-    if
-	%% If I'm not running the test will be made later.
-	HasDown == true, ImRunning == yes ->
-	    spawn_link(?MODULE, detect_partitioned_network, [self(), Node]);
-	true ->
-	    ignore
-    end,
-    {noreply, State};
+handle_info({nodeup, Node}, State) ->
+    State2 = remote_node_status(Node, up, State),
+    State3 = check_mnesia_down(Node, State2),
+    {noreply, State3};
 
-handle_info({nodedown, _Node}, State) ->
-    %% Ignore, we are only caring about nodeup's
-    {noreply, State};
+handle_info({nodedown, Node}, State) ->
+    State2 = remote_node_status(Node, down, State),
+    {noreply, State2};
 
 handle_info({disk_log, _Node, Log, Info}, State) ->
     case Info of
@@ -665,10 +669,12 @@ get_env(E) ->
 env() ->
     [
      access_module,
+     allow_index_on_key,
      auto_repair,
      backup_module,
      debug,
      dir,
+     dump_disc_copies_at_startup,
      dump_log_load_regulation,
      dump_log_time_threshold,
      dump_log_update_in_place,
@@ -677,19 +683,23 @@ env() ->
      extra_db_nodes,
      ignore_fallback_at_startup,
      fallback_error_function,
+     fold_chunk_size,
      max_wait_for_decision,
      schema_location,
      core_dir,
      pid_sort_order,
      no_table_loaders,
      dc_dump_limit,
-     send_compressed
+     send_compressed,
+     schema
     ].
 
 default_env(access_module) ->
     mnesia;
 default_env(auto_repair) ->
     true;
+default_env(allow_index_on_key) ->
+    false;
 default_env(backup_module) ->
     mnesia_backup;
 default_env(debug) ->
@@ -697,6 +707,8 @@ default_env(debug) ->
 default_env(dir) ->
     Name = lists:concat(["Mnesia.", node()]),
     filename:absname(Name);
+default_env(dump_disc_copies_at_startup) ->
+    true;
 default_env(dump_log_load_regulation) ->
     false;
 default_env(dump_log_time_threshold) ->
@@ -713,6 +725,8 @@ default_env(ignore_fallback_at_startup) ->
     false;
 default_env(fallback_error_function) ->
     {mnesia, lkill};
+default_env(fold_chunk_size) ->
+    100;
 default_env(max_wait_for_decision) ->
     infinity;
 default_env(schema_location) ->
@@ -726,17 +740,17 @@ default_env(no_table_loaders) ->
 default_env(dc_dump_limit) ->
     4;
 default_env(send_compressed) ->
-    0.
+    0;
+default_env(schema) ->
+    [].
 
 check_type(Env, Val) ->
-    case catch do_check_type(Env, Val) of
-	{'EXIT', _Reason} ->
-	    exit({bad_config, Env, Val});
-	NewVal ->
-	    NewVal
+    try do_check_type(Env, Val)
+    catch error:_ -> exit({bad_config, Env, Val})
     end.
 
 do_check_type(access_module, A) when is_atom(A) -> A;
+do_check_type(allow_index_on_key, B) -> bool(B);
 do_check_type(auto_repair, B) -> bool(B);
 do_check_type(backup_module, B) when is_atom(B) -> B;
 do_check_type(debug, debug) -> debug;
@@ -746,6 +760,7 @@ do_check_type(debug, trace) -> trace;
 do_check_type(debug, true) -> debug;
 do_check_type(debug, verbose) -> verbose;
 do_check_type(dir, V) -> filename:absname(V);
+do_check_type(dump_disc_copies_at_startup, B) -> bool(B);
 do_check_type(dump_log_load_regulation, B) -> bool(B);
 do_check_type(dump_log_time_threshold, I) when is_integer(I), I > 0 -> I;
 do_check_type(dump_log_update_in_place, B) -> bool(B);
@@ -759,6 +774,8 @@ do_check_type(extra_db_nodes, L) when is_list(L) ->
 	     (A) when is_atom(A) -> true
 	  end,
     lists:filter(Fun, L);
+do_check_type(fold_chunk_size, I) when is_integer(I), I > 0;
+				       I =:= infinity -> I;
 do_check_type(max_wait_for_decision, infinity) -> infinity;
 do_check_type(max_wait_for_decision, I) when is_integer(I), I > 0 -> I;
 do_check_type(schema_location, M) -> media(M);
@@ -772,7 +789,8 @@ do_check_type(pid_sort_order, "standard") -> standard;
 do_check_type(pid_sort_order, _) -> false;
 do_check_type(no_table_loaders, N) when is_integer(N), N > 0 -> N;
 do_check_type(dc_dump_limit,N) when is_number(N), N > 0 -> N;
-do_check_type(send_compressed, L) when is_integer(L), L >= 0, L =< 9 -> L.
+do_check_type(send_compressed, L) when is_integer(L), L >= 0, L =< 9 -> L;
+do_check_type(schema, L) when is_list(L) -> L.
 
 bool(true) -> true;
 bool(false) -> false.
@@ -782,12 +800,12 @@ media(opt_disc) -> opt_disc;
 media(ram) -> ram.
 
 patch_env(Env, Val) ->
-    case catch do_check_type(Env, Val) of
-	{'EXIT', _Reason} ->
-	    {error, {bad_type, Env, Val}};
+    try do_check_type(Env, Val) of
 	NewVal ->
 	    application_controller:set_env(mnesia, Env, NewVal),
 	    NewVal
+    catch error:_ ->
+	    {error, {bad_type, Env, Val}}
     end.
 
 detect_partitioned_network(Mon, Node) ->
@@ -830,3 +848,48 @@ report_inconsistency([{badrpc, _Reason} | Replies], Context, Status) ->
     report_inconsistency(Replies, Context, Status);
 report_inconsistency([], _Context, Status) ->
     Status.
+
+remote_node_status(Node, Status, State) ->
+    {ok, Nodes} = mnesia_schema:read_nodes(),
+    case lists:member(Node, Nodes) of
+	true ->
+	    update_node_status({Node, Status}, State);
+	_ ->
+	    State
+    end.
+
+update_node_status({Node, down}, State = #state{remote_node_status = RNodeS}) ->
+    RNodeS2 = lists:ukeymerge(1, [{Node, down}], RNodeS),
+    State#state{remote_node_status = RNodeS2};
+update_node_status({Node, up}, State = #state{remote_node_status = RNodeS}) ->
+    case lists:keyfind(Node, 1, RNodeS) of
+	{Node, down} ->
+	    RNodeS2 = lists:ukeymerge(1, [{Node, up}], RNodeS),
+	    State#state{remote_node_status = RNodeS2};
+	_ ->
+	    State
+    end.
+
+check_raise_conditon_nodeup(Node, State = #state{remote_node_status = RNodeS}) ->
+    case lists:keyfind(Node, 1, RNodeS) of
+	{Node, up} ->
+	    self() ! {check_nodeup, Node};
+	_ ->
+	    ignore
+    end,
+    State#state{remote_node_status = lists:keydelete(Node, 1, RNodeS)}.
+
+check_mnesia_down(Node, State = #state{remote_node_status = RNodeS}) ->
+    %% Check if the network has been partitioned
+    %% due to communication failure.
+
+    HasDown   = mnesia_recover:has_mnesia_down(Node),
+    ImRunning = mnesia_lib:is_running(),
+    if
+	%% If I'm not running the test will be made later.
+	HasDown == true, ImRunning == yes ->
+	    spawn_link(?MODULE, detect_partitioned_network, [self(), Node]),
+	    State#state{remote_node_status = lists:keydelete(Node, 1, RNodeS)};
+	true ->
+	    State
+    end.
diff --git a/lib/mnesia/src/mnesia_recover.erl b/lib/mnesia/src/mnesia_recover.erl
index 7aa03bda37..b204fb282f 100644
--- a/lib/mnesia/src/mnesia_recover.erl
+++ b/lib/mnesia/src/mnesia_recover.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -178,7 +179,8 @@ log_decision(D) ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason); 
+	{'EXIT', _Reason} ->
+	    mnesia_lib:other_val(Var);
 	Value -> Value
     end.
 
@@ -369,11 +371,8 @@ log_master_nodes2([], _UseDir, IsRunning, WorstRes) ->
 get_master_node_info() ->
     Tab = mnesia_decision,
     Pat = {master_nodes, '_', '_'},
-    case catch mnesia_lib:db_match_object(ram_copies,Tab, Pat) of
-	{'EXIT', _} ->
-	    [];
-	Masters ->
-	    Masters
+    try mnesia_lib:db_match_object(ram_copies,Tab, Pat)
+    catch error:_ -> []
     end.
 
 get_master_node_tables() ->
@@ -381,9 +380,8 @@ get_master_node_tables() ->
     [Tab || {master_nodes, Tab, _Nodes} <- Masters].
 
 get_master_nodes(Tab) ->
-    case catch ?ets_lookup_element(mnesia_decision, Tab, 3) of
-	{'EXIT', _} -> [];
-	Nodes  -> Nodes
+    try ?ets_lookup_element(mnesia_decision, Tab, 3)
+    catch error:_ -> []
     end.
 
 %% Determine what has happened to the transaction
@@ -481,8 +479,6 @@ load_decision_tab() ->
     load_decision_tab(Cont, load_decision_tab),
     mnesia_log:close_decision_tab().
 
-load_decision_tab(eof, _InitBy) ->
-    ok;
 load_decision_tab(Cont, InitBy) ->
     case mnesia_log:chunk_decision_tab(Cont) of
 	{Cont2, Decisions} ->
@@ -515,8 +511,6 @@ dump_decision_log(InitBy) ->
     Cont = mnesia_log:prepare_decision_log_dump(),
     perform_dump_decision_log(Cont, InitBy).
 
-perform_dump_decision_log(eof, _InitBy) ->
-    confirm_decision_log_dump();
 perform_dump_decision_log(Cont, InitBy) when InitBy == startup ->
     case mnesia_log:chunk_decision_log(Cont) of
 	{Cont2, Decisions} ->
@@ -685,12 +679,29 @@ handle_call({connect_nodes, Ns}, From, State) ->
 	    %% called from handle_info
 	    gen_server:reply(From, {[], AlreadyConnected}),
 	    {noreply, State};
-	GoodNodes ->
+	ProbablyGoodNodes ->
 	    %% Now we have agreed upon a protocol with some new nodes
-	    %% and we may use them when we recover transactions
+	    %% and we may use them when we recover transactions.
+	    %%
+	    %% Just in case Mnesia was stopped on some of those nodes
+	    %% between the protocol negotiation and now, we check one
+	    %% more time the state of Mnesia.
+	    %%
+	    %% Of course, there is still a chance that mnesia_down
+	    %% events occur during this check and we miss them. To
+	    %% prevent it, handle_cast({mnesia_down, ...}, ...) removes
+	    %% the down node again, in addition to mnesia_down/1.
+	    %%
+	    %% See a comment in handle_cast({mnesia_down, ...}, ...).
+	    Verify = fun(N) ->
+			     Run = mnesia_lib:is_running(N),
+			     Run =:= yes orelse Run =:= starting
+		     end,
+	    GoodNodes = [N || N <- ProbablyGoodNodes, Verify(N)],
+
 	    mnesia_lib:add_list(recover_nodes, GoodNodes),
 	    cast({announce_all, GoodNodes}),
-	    case get_master_nodes(schema) of 
+	    case get_master_nodes(schema) of
 		[] ->
 		    Context = starting_partitioned_network,
 		    mnesia_monitor:detect_inconcistency(GoodNodes, Context);
@@ -838,6 +849,14 @@ handle_cast({what_decision, Node, OtherD}, State) ->
     {noreply, State};
 
 handle_cast({mnesia_down, Node}, State) ->
+    %% The node was already removed from recover_nodes in mnesia_down/1,
+    %% but we do it again here in the mnesia_recover process, in case
+    %% another event incorrectly added it back. This can happen during
+    %% Mnesia startup which takes time betweenthe connection, the
+    %% protocol negotiation and the merge of the schema.
+    %%
+    %% See a comment in handle_call({connect_nodes, ...), ...).
+    mnesia_lib:del(recover_nodes, Node),
     case State#state.unclear_decision of
 	undefined ->
 	    {noreply, State};
@@ -995,7 +1014,7 @@ decision(Tid) ->
     decision(Tid, tabs()).
 
 decision(Tid, [Tab | Tabs]) ->
-    case catch ?ets_lookup(Tab, Tid) of
+    try ?ets_lookup(Tab, Tid) of
 	[D] when is_record(D, decision) ->
 	    D;
 	[C] when is_record(C, transient_decision) ->
@@ -1005,8 +1024,8 @@ decision(Tid, [Tab | Tabs]) ->
 		      ram_nodes = []
 		     };
 	[] ->
-	    decision(Tid, Tabs);
-	{'EXIT', _} ->
+	    decision(Tid, Tabs)
+    catch error:_ ->
 	    %% Recently switched transient decision table
 	    decision(Tid, Tabs)
     end;
@@ -1017,11 +1036,8 @@ outcome(Tid, Default) ->
     outcome(Tid, Default, tabs()).
 
 outcome(Tid, Default, [Tab | Tabs]) ->
-    case catch ?ets_lookup_element(Tab, Tid, 3) of
-	{'EXIT', _} ->
-	    outcome(Tid, Default, Tabs);
-	Val ->
-	    Val
+    try ?ets_lookup_element(Tab, Tid, 3)
+    catch error:_ -> outcome(Tid, Default, Tabs)
     end;
 outcome(_Tid, Default, []) ->
     Default.
diff --git a/lib/mnesia/src/mnesia_registry.erl b/lib/mnesia/src/mnesia_registry.erl
index 202689ae5e..55ddc3d2fd 100644
--- a/lib/mnesia/src/mnesia_registry.erl
+++ b/lib/mnesia/src/mnesia_registry.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1998-2010. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_schema.erl b/lib/mnesia/src/mnesia_schema.erl
index 6e43052fb0..0e4017e4c3 100644
--- a/lib/mnesia/src/mnesia_schema.erl
+++ b/lib/mnesia/src/mnesia_schema.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -28,6 +29,16 @@
 -module(mnesia_schema).
 
 -export([
+         add_backend_type/2,
+	 do_add_backend_type/2,
+	 delete_backend_type/1,
+	 do_delete_backend_type/1,
+	 backend_types/0,
+	 add_index_plugin/3,
+	 do_add_index_plugin/3,
+	 delete_index_plugin/1,
+	 do_delete_index_plugin/1,
+	 index_plugins/0,
          add_snmp/2,
          add_table_copy/3,
          add_table_index/2,
@@ -54,14 +65,16 @@
          dump_tables/1,
          ensure_no_schema/1,
 	 get_create_list/1,
-         get_initial_schema/2,
+         get_initial_schema/3,
 	 get_table_properties/1,
          info/0,
          info/1,
          init/1,
+	 init_backends/0,
          insert_cstruct/3,
 	 is_remote_member/1,
          list2cs/1,
+         list2cs/2,
          lock_schema/0,
          merge_schema/0,
          merge_schema/1,
@@ -109,7 +122,8 @@
 	 do_delete_table/1,
 	 do_read_table_property/2,
 	 do_delete_table_property/2,
- 	 do_write_table_property/2]).
+         do_write_table_property/2,
+         do_change_table_copy_type/3]).
 
 -include("mnesia.hrl").
 -include_lib("kernel/include/file.hrl").
@@ -137,12 +151,30 @@ init(IgnoreFallback) ->
     verbose("Schema initiated from: ~p~n", [Source]),
     set({schema, tables}, []),
     set({schema, local_tables}, []),
+    do_set_schema(schema),
     Tabs = set_schema(?ets_first(schema)),
     lists:foreach(fun(Tab) -> clear_whereabouts(Tab) end, Tabs),
     set({schema, where_to_read}, node()),
     set({schema, load_node}, node()),
     set({schema, load_reason}, initial),
-    mnesia_controller:add_active_replica(schema, node()).
+    mnesia_controller:add_active_replica(schema, node()),
+    init_backends().
+
+
+init_backends() ->
+    Backends = lists:foldl(fun({Alias, Mod}, Acc) ->
+				   orddict:append(Mod, Alias, Acc)
+			   end, orddict:new(), get_ext_types()),
+    [init_backend(Mod, Aliases) || {Mod, Aliases} <- Backends],
+    ok.
+
+init_backend(Mod, [_|_] = Aliases) ->
+    case Mod:init_backend() of
+	ok ->
+	    Mod:add_aliases(Aliases);
+	Error ->
+	    mnesia:abort({backend_init_error, Error})
+    end.
 
 exit_on_error({error, Reason}) ->
     exit(Reason);
@@ -151,7 +183,7 @@ exit_on_error(GoodRes) ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', Reason} -> mnesia_lib:other_val(Var, Reason);
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
 	Value -> Value
     end.
 
@@ -179,6 +211,7 @@ do_set_schema(Tab, Cs) ->
     set({Tab, ram_copies}, Cs#cstruct.ram_copies),
     set({Tab, disc_copies}, Cs#cstruct.disc_copies),
     set({Tab, disc_only_copies}, Cs#cstruct.disc_only_copies),
+    set({Tab, external_copies}, Cs#cstruct.external_copies),
     set({Tab, load_order}, Cs#cstruct.load_order),
     set({Tab, access_mode}, Cs#cstruct.access_mode),
     set({Tab, majority}, Cs#cstruct.majority),
@@ -194,15 +227,21 @@ do_set_schema(Tab, Cs) ->
     set({Tab, arity}, Arity),
     RecName =  Cs#cstruct.record_name,
     set({Tab, record_name}, RecName),
-    set({Tab, record_validation}, {RecName, Arity, Type}),
     set({Tab, wild_pattern}, wild(RecName, Arity)),
-    set({Tab, index}, Cs#cstruct.index),
+    set({Tab, index}, [P || {P,_} <- Cs#cstruct.index]),
+    case Cs#cstruct.index of
+        [] ->
+            set({Tab, index_info}, mnesia_index:index_info(Type, []));
+        _ ->
+            ignore
+    end,
     %% create actual index tabs later
     set({Tab, cookie}, Cs#cstruct.cookie),
     set({Tab, version}, Cs#cstruct.version),
     set({Tab, cstruct}, Cs),
     Storage = mnesia_lib:schema_cs_to_storage_type(node(), Cs),
     set({Tab, storage_type}, Storage),
+    set_record_validation(Tab, Storage, RecName, Arity, Type),
     mnesia_lib:add({schema, tables}, Tab),
     Ns = mnesia_lib:cs_to_nodes(Cs),
     case lists:member(node(), Ns) of
@@ -212,7 +251,24 @@ do_set_schema(Tab, Cs) ->
             mnesia_lib:add({schema, local_tables}, Tab);
         false ->
             ignore
-    end.
+    end,
+    set_ext_types(Tab, get_ext_types(), Cs#cstruct.external_copies).
+
+set_record_validation(Tab, {ext,Alias,Mod}, RecName, Arity, Type) ->
+    set({Tab, record_validation}, {RecName, Arity, Type, Alias, Mod});
+set_record_validation(Tab, _, RecName, Arity, Type) ->
+    set({Tab, record_validation}, {RecName, Arity, Type}).
+
+set_ext_types(Tab, ExtTypes, ExtCopies) ->
+    lists:foreach(
+      fun({Type, _} = Key) ->
+	      Nodes = case lists:keyfind(Key, 1, ExtCopies) of
+			  {_, Ns} -> Ns;
+			  false   -> []
+		      end,
+	      set({Tab, Type}, Nodes)
+      end, ExtTypes).
+
 
 wild(RecName, Arity) ->
     Wp0 = list_to_tuple(lists:duplicate(Arity, '_')),
@@ -262,7 +318,7 @@ incr_version(Cs) ->
             [] -> {Major + 1, 0};    % All replicas are active
             _ -> {Major, Minor + 1}  % Some replicas are inactive
         end,
-    Cs#cstruct{version = {V, {node(), now()}}}.
+    Cs#cstruct{version = {V, {node(), erlang:timestamp()}}}.
 
 %% Returns table name
 insert_cstruct(Tid, Cs, KeepWhereabouts) ->
@@ -524,9 +580,14 @@ do_read_disc_schema(Fname, Keep) ->
     Res.
 
 get_initial_schema(SchemaStorage, Nodes) ->
+    get_initial_schema(SchemaStorage, Nodes, []).
+
+get_initial_schema(SchemaStorage, Nodes, Properties) ->	%
+    UserProps = initial_schema_properties(Properties),
     Cs = #cstruct{name = schema,
 		  record_name = schema,
-		  attributes = [table, cstruct]},
+		  attributes = [table, cstruct],
+		  user_properties = UserProps},
     Cs2 =
 	case SchemaStorage of
         ram_copies -> Cs#cstruct{ram_copies = Nodes};
@@ -534,6 +595,35 @@ get_initial_schema(SchemaStorage, Nodes) ->
     end,
     cs2list(Cs2).
 
+initial_schema_properties(Props0) ->
+    DefaultProps = remove_duplicates(mnesia_monitor:get_env(schema)),
+    Props = lists:foldl(
+	      fun({K,V}, Acc) ->
+		      lists:keystore(K, 1, Acc, {K,V})
+	      end, DefaultProps, remove_duplicates(Props0)),
+    initial_schema_properties_(Props).
+
+initial_schema_properties_([{backend_types, Types}|Props]) ->
+    lists:foreach(fun({Name, Module}) ->
+			  verify_backend_type(Name, Module)
+		  end, Types),
+    [{mnesia_backend_types, Types}|initial_schema_properties_(Props)];
+initial_schema_properties_([{index_plugins, Plugins}|Props]) ->
+    lists:foreach(fun({Name, Module, Function}) ->
+			  verify_index_plugin(Name, Module, Function)
+		  end, Plugins),
+    [{mnesia_index_plugins, Plugins}|initial_schema_properties_(Props)];
+initial_schema_properties_([P|_Props]) ->
+    mnesia:abort({bad_schema_property, P});
+initial_schema_properties_([]) ->
+    [].
+
+remove_duplicates([{K,_} = H|T]) ->
+    [H | remove_duplicates([X || {K1,_} = X <- T,
+				 K1 =/= K])];
+remove_duplicates([]) ->
+    [].
+
 read_cstructs_from_disc() ->
     %% Assumptions:
     %% - local schema lock in global
@@ -550,8 +640,9 @@ read_cstructs_from_disc() ->
 		    {type, set}],
 	    case dets:open_file(make_ref(), Args) of
 		{ok, Tab} ->
+                    ExtTypes = get_ext_types_disc(),
 		    Fun = fun({_, _, List}) ->
-				  {continue, list2cs(List)}
+				  {continue, list2cs(List, ExtTypes)}
 			  end,
 		    Cstructs = dets:traverse(Tab, Fun),
 		    dets:close(Tab),
@@ -631,7 +722,7 @@ do_insert_schema_ops(_Store, []) ->
 
 api_list2cs(List) when is_list(List) ->
     Name = pick(unknown, name, List, must),
-    Keys = check_keys(Name, List, record_info(fields, cstruct)),
+    Keys = check_keys(Name, List),
     check_duplicates(Name, Keys),
     list2cs(List);
 api_list2cs(Other) ->
@@ -645,55 +736,57 @@ cs2list(Cs) when is_record(Cs, cstruct) ->
     rec2list(Tags, Tags, 2, Cs);
 cs2list(CreateList) when is_list(CreateList) ->
     CreateList;
-%% 4.6
-cs2list(Cs) when element(1, Cs) == cstruct, tuple_size(Cs) == 19 ->
-    Tags = [name,type,ram_copies,disc_copies,disc_only_copies,
+
+cs2list(Cs) when element(1, Cs) == cstruct, tuple_size(Cs) == 20 ->
+    Tags = [name,type,
+	    ram_copies,disc_copies,disc_only_copies,external_copies,
 	    load_order,access_mode,majority,index,snmp,local_content,
 	    record_name,attributes,
 	    user_properties,frag_properties,storage_properties,
 	    cookie,version],
     rec2list(Tags, Tags, 2, Cs);
-%% 4.4.19
-cs2list(Cs) when element(1, Cs) == cstruct, tuple_size(Cs) == 18 ->
+%% since vsn-4.6 (protocol 8.2 or older)
+cs2list(Cs) when element(1, Cs) == cstruct, tuple_size(Cs) == 19 ->
     Tags = [name,type,ram_copies,disc_copies,disc_only_copies,
 	    load_order,access_mode,majority,index,snmp,local_content,
-	    record_name,attributes,user_properties,frag_properties,
-	    cookie,version],
-    rec2list(Tags, Tags, 2, Cs);
-%% 4.4.18 and earlier
-cs2list(Cs) when element(1, Cs) == cstruct, tuple_size(Cs) == 17 ->
-    Tags = [name,type,ram_copies,disc_copies,disc_only_copies,
-	    load_order,access_mode,index,snmp,local_content,
-	    record_name,attributes,user_properties,frag_properties,
+	    record_name,attributes,
+	    user_properties,frag_properties,storage_properties,
 	    cookie,version],
     rec2list(Tags, Tags, 2, Cs).
 
 cs2list(false, Cs) ->
     cs2list(Cs);
-cs2list(ver4_4_18, Cs) -> %% Or earlier
-    Orig = record_info(fields, cstruct),
-    Tags = [name,type,ram_copies,disc_copies,disc_only_copies,
-	    load_order,access_mode,index,snmp,local_content,
-	    record_name,attributes,user_properties,frag_properties,
-	    cookie,version],
-    rec2list(Tags, Orig, 2, Cs);
-cs2list(ver4_4_19, Cs) ->
-    Orig = record_info(fields, cstruct),
-    Tags = [name,type,ram_copies,disc_copies,disc_only_copies,
-	    load_order,access_mode,majority,index,snmp,local_content,
-	    record_name,attributes,user_properties,frag_properties,
-	    cookie,version],
-    rec2list(Tags, Orig, 2, Cs);
-cs2list(ver4_6, Cs) ->
+cs2list({8,3}, Cs) ->
+    cs2list(Cs);
+cs2list({8,Minor}, Cs) when Minor =:= 2; Minor =:= 1 ->
     Orig = record_info(fields, cstruct),
     Tags = [name,type,ram_copies,disc_copies,disc_only_copies,
 	    load_order,access_mode,majority,index,snmp,local_content,
 	    record_name,attributes,
 	    user_properties,frag_properties,storage_properties,
 	    cookie,version],
-    rec2list(Tags, Orig, 2, Cs).
-
+    CsList = rec2list(Tags, Orig, 2, Cs),
+    case proplists:get_value(index, CsList, []) of
+	[] -> CsList;
+	NewFormat ->
+	    OldFormat = [Pos || {Pos, _Pref} <- NewFormat],
+	    lists:keyreplace(index, 1, CsList, {index, OldFormat})
+    end.
 
+rec2list([index | Tags], [index|Orig], Pos, Rec) ->
+    Val = element(Pos, Rec),
+    [{index, lists:map(
+	       fun({_, _Type}=P) -> P;
+		  (P) when is_integer(P); is_atom(P) -> {P, ordered}
+	       end, Val)} | rec2list(Tags, Orig, Pos + 1, Rec)];
+rec2list([external_copies | Tags], Orig0, Pos, Rec) ->
+    Orig = case Orig0 of
+	       [external_copies|Rest] -> Rest;
+	       _ -> Orig0
+	   end,
+    Val = element(Pos, Rec),
+    [{Alias, Ns} || {{Alias,_}, Ns} <- Val]
+	++ rec2list(Tags, Orig, Pos+1, Rec);
 rec2list([Tag | Tags], [Tag | Orig], Pos, Rec) ->
     Val = element(Pos, Rec),
     [{Tag, Val} | rec2list(Tags, Orig, Pos + 1, Rec)];
@@ -716,14 +809,19 @@ convert_cs(Version, Cs) ->
     Fields = [Value || {_, Value} <- cs2list(Version, Cs)],
     list_to_tuple([cstruct|Fields]).
 
-list2cs(List) when is_list(List) ->
+list2cs(List) ->
+    list2cs(List, get_ext_types()).
+
+list2cs(List, ExtTypes) when is_list(List) ->
     Name = pick(unknown, name, List, must),
     Type = pick(Name, type, List, set),
     Rc0 = pick(Name, ram_copies, List, []),
     Dc = pick(Name, disc_copies, List, []),
     Doc = pick(Name, disc_only_copies, List, []),
-    Rc = case {Rc0, Dc, Doc} of
-             {[], [], []} -> [node()];
+
+    Ext = pick_external_copies(List, ExtTypes),
+    Rc = case {Rc0, Dc, Doc, Ext} of
+             {[], [], [], []} -> [node()];
              _ -> Rc0
          end,
     LC = pick(Name, local_content, List, false),
@@ -741,8 +839,6 @@ list2cs(List) when is_list(List) ->
     Ix = pick(Name, index, List, []),
     verify({alt, [nil, list]}, mnesia_lib:etype(Ix),
 	   {bad_type, Name, {index, [Ix]}}),
-    Ix2 = [attr_to_pos(I, Attrs) || I <- Ix],
-
     Frag = pick(Name, frag_properties, List, []),
     verify({alt, [nil, list]}, mnesia_lib:etype(Frag),
 	   {badarg, Name, {frag_properties, Frag}}),
@@ -769,24 +865,48 @@ list2cs(List) when is_list(List) ->
     DetsOpts = proplists:get_value(dets, BEProps, []),
     is_list(DetsOpts) orelse mnesia:abort({badarg, Name, {dets, DetsOpts}}),
     [CheckProp(Prop, BadDetsOpts) || Prop <- DetsOpts],
-    #cstruct{name = Name,
-             ram_copies = Rc,
-             disc_copies = Dc,
-             disc_only_copies = Doc,
-             type = Type,
-             index = Ix2,
-             snmp = Snmp,
-             load_order = LoadOrder,
-             access_mode = AccessMode,
-	     majority = Majority,
-             local_content = LC,
-	     record_name = RecName,
-             attributes = Attrs,
-             user_properties = lists:sort(UserProps),
-	     frag_properties = lists:sort(Frag),
-	     storage_properties = lists:sort(BEProps),
-             cookie = Cookie,
-             version = Version}.
+
+    case lists:keymember(mnesia, 1, application:which_applications()) of
+        true ->
+            Keys = check_keys(Name, List),
+            check_duplicates(Name, Keys);
+        false ->
+            %% check_keys/2 cannot be executed when mnesia is not
+            %% running, due to it not being possible to read what ext
+            %% backends are loaded.
+            %%% this doesn't work - disabled for now:
+	    %%%Keys = check_keys(Name, List, record_info(fields, cstruct)),
+	    %%%check_duplicates(Name, Keys)
+            ignore
+    end,
+
+    Cs0 = #cstruct{name = Name,
+		   ram_copies = Rc,
+		   disc_copies = Dc,
+		   disc_only_copies = Doc,
+		   external_copies = Ext,
+		   type = Type,
+		   index = Ix,
+		   snmp = Snmp,
+		   load_order = LoadOrder,
+		   access_mode = AccessMode,
+		   majority = Majority,
+		   local_content = LC,
+		   record_name = RecName,
+		   attributes = Attrs,
+		   user_properties = lists:sort(UserProps),
+		   frag_properties = lists:sort(Frag),
+                   storage_properties = lists:sort(BEProps),
+		   cookie = Cookie,
+		   version = Version},
+    case Ix of
+	[] -> Cs0;
+	[_|_] ->
+	    Ix2 = expand_index_attrs(Cs0),
+	    Cs0#cstruct{index = Ix2}
+    end;
+list2cs(Other, _ExtTypes) ->
+    mnesia:abort({badarg, Other}).
 
 pick(Tab, Key, List, Default) ->
     case lists:keysearch(Key, 1, List) of
@@ -800,6 +920,79 @@ pick(Tab, Key, List, Default) ->
 	    mnesia:abort({bad_type, Tab, BadArg})
     end.
 
+pick_external_copies(_List, []) ->
+    [];
+pick_external_copies(List, ExtTypes) ->
+    lists:foldr(
+      fun({K, Val}, Acc) ->
+	      case lists:keyfind(K, 1, ExtTypes) of
+		  false ->
+		      Acc;
+		  {_, Mod} ->
+		      [{{K,Mod}, Val}|Acc]
+	      end
+      end, [], List).
+
+expand_storage_type(S) when S==ram_copies;
+			    S==disc_copies;
+			    S==disc_only_copies ->
+    S;
+expand_storage_type(S) ->
+    case lists:keyfind(S, 1, get_ext_types()) of
+	false ->
+	    mnesia:abort({bad_type, {storage_type, S}});
+	{Alias, Mod} ->
+	    {ext, Alias, Mod}
+    end.
+
+get_ext_types() ->
+    get_schema_user_property(mnesia_backend_types).
+
+get_index_plugins() ->
+    get_schema_user_property(mnesia_index_plugins).
+
+get_schema_user_property(Key) ->
+    Tab = schema,
+    %% Must work reliably both within transactions and outside of transactions
+    Res = case get(mnesia_activity_state) of
+	      undefined ->
+		  dirty_read_table_property(Tab, Key);
+	      _ ->
+		  do_read_table_property(Tab, Key)
+	  end,
+    case Res of
+	undefined ->
+	    [];
+	{_, Types} ->
+	    Types
+    end.
+
+get_ext_types_disc() ->
+    try get_ext_types_disc_()
+    catch
+	error:_ ->[]
+    end.
+
+get_ext_types_disc_() ->
+    case mnesia_schema:remote_read_schema() of
+        {ok, _, Prop} ->
+            K1 = user_properties,
+            case lists:keyfind(K1, 1, Prop) of
+                {K1, UserProp} ->
+                    K2 = mnesia_backend_types,
+                    case lists:keyfind(K2, 1, UserProp) of
+                        {K2, Types} ->
+                            Types;
+                        _ ->
+                            []
+                    end;
+                _ ->
+                    []
+            end;
+        _ ->
+            []
+    end.
+
 %% Convert attribute name to integer if neccessary
 attr_tab_to_pos(_Tab, Pos) when is_integer(Pos) ->
     Pos;
@@ -807,6 +1000,7 @@ attr_tab_to_pos(Tab, Attr) ->
     attr_to_pos(Attr, val({Tab, attributes})).
 
 %% Convert attribute name to integer if neccessary
+attr_to_pos({_} = P, _) -> P;
 attr_to_pos(Pos, _Attrs) when is_integer(Pos) ->
     Pos;
 attr_to_pos(Attr, Attrs) when is_atom(Attr) ->
@@ -821,8 +1015,18 @@ attr_to_pos(Attr, [_ | Attrs], Pos) ->
 attr_to_pos(Attr, _, _) ->
     mnesia:abort({bad_type, Attr}).
 
+check_keys(Tab, Attrs) ->
+    Types = [T || {T,_} <- get_ext_types()],
+    check_keys(Tab, Attrs, Types ++ record_info(fields, cstruct)).
+
 check_keys(Tab, [{Key, _Val} | Tail], Items) ->
-    case lists:member(Key, Items) of
+    Key1 = if
+               is_tuple(Key) ->
+                   element(1, Key);
+               true ->
+                   Key
+           end,
+    case lists:member(Key1, Items) of
         true ->  [Key | check_keys(Tab, Tail, Items)];
         false -> mnesia:abort({badarg, Tab, Key})
     end;
@@ -846,7 +1050,92 @@ has_duplicates([]) ->
     false.
 
 %% This is the only place where we check the validity of data
-verify_cstruct(Cs) when is_record(Cs, cstruct) ->
+
+verify_cstruct(#cstruct{} = Cs) ->
+    assert_correct_cstruct(Cs),
+    Cs1 = verify_external_copies(
+	    Cs#cstruct{index = expand_index_attrs(Cs)}),
+    assert_correct_cstruct(Cs1),
+    Cs1.
+
+expand_index_attrs(#cstruct{index = Ix, attributes = Attrs,
+			    name = Tab} = Cs) ->
+    Prefered = prefered_index_types(Cs),
+    expand_index_attrs(Ix, Tab, Attrs, Prefered).
+
+expand_index_attrs(Ix, Tab, Attrs, Prefered) ->
+    lists:map(fun(P) when is_integer(P); is_atom(P) ->
+		      {attr_to_pos(P, Attrs), Prefered};
+		 ({A} = P) when is_atom(A) ->
+		      {P, Prefered};
+		 ({P, Type}) ->
+		      {attr_to_pos(P, Attrs), Type};
+		 (_Other) ->
+		      mnesia:abort({bad_type, Tab, {index, Ix}})
+	      end, Ix).
+
+prefered_index_types(#cstruct{external_copies = Ext}) ->
+    ExtTypes = [mnesia_lib:semantics(S, index_types) ||
+		   {S,Ns} <- Ext, Ns =/= []],
+    case intersect_types(ExtTypes) of
+	[] -> ordered;
+	[Pref|_] -> Pref
+    end.
+
+intersect_types([]) ->
+    [];
+intersect_types([S1, S2|Rest]) ->
+    intersect_types([S1 -- (S1 -- S2)|Rest]);
+intersect_types([S]) ->
+    S.
+
+verify_external_copies(#cstruct{external_copies = []} = Cs) ->
+    Cs;
+verify_external_copies(#cstruct{name = Tab, external_copies = EC} = Cs) ->
+    Bad = {bad_type, Tab, {external_copies, EC}},
+    AllECNodes = lists:concat([Ns || {_, Ns} <- EC,
+                                     is_list(Ns)]),
+    verify(true, length(lists:usort(AllECNodes)) == length(AllECNodes), Bad),
+    CsL = cs2list(Cs),
+    CsL1 = lists:foldl(
+	     fun({{Alias, Mod}, Ns} = _X, CsLx) ->
+		     BadTab = fun(Why) ->
+				      {Why, Tab, {{ext, Alias, Mod},Ns}}
+			      end,
+		     verify(atom, mnesia_lib:etype(Mod), BadTab),
+		     verify(true, fun() ->
+					  lists:all(fun is_atom/1, Ns)
+				  end, BadTab),
+		     check_semantics(Mod, Alias, BadTab, Cs),
+		     try Mod:check_definition(Alias, Tab, Ns, CsLx) of
+			 ok ->
+			     CsLx;
+			 {ok, CsLx1} ->
+			     CsLx1;
+			 {error, Reason} ->
+			     mnesia:abort(BadTab(Reason))
+		     catch
+			 error:E ->
+			     mnesia:abort(BadTab(E))
+		     end;
+		(_, CsLx) ->
+		     CsLx
+	     end, CsL, EC),
+    list2cs(CsL1).
+
+check_semantics(Mod, Alias, BadTab, #cstruct{type = Type}) ->
+    Ext = {ext, Alias, Mod},
+    case lists:member(mnesia_lib:semantics(Ext, storage), [ram_copies, disc_copies,
+							   disc_only_copies]) of
+	false -> mnesia:abort(BadTab(invalid_storage));
+	true  -> ok
+    end,
+    case lists:member(Type, mnesia_lib:semantics(Ext, types)) of
+	false -> mnesia:abort(BadTab(bad_type));
+	true  -> ok
+    end.
+
+assert_correct_cstruct(Cs) when is_record(Cs, cstruct) ->
     verify_nodes(Cs),
 
     Tab = Cs#cstruct.name,
@@ -887,22 +1176,30 @@ verify_cstruct(Cs) when is_record(Cs, cstruct) ->
                 Attrs),
 
     Index = Cs#cstruct.index,
+
     verify({alt, [nil, list]}, mnesia_lib:etype(Index),
 	   {bad_type, Tab, {index, Index}}),
+    IxPlugins = get_index_plugins(),
 
+    AllowIndexOnKey = check_if_allow_index_on_key(),
     IxFun =
-        fun(Pos) ->
-                verify(true, fun() ->
-                                     if
-					 is_integer(Pos),
-                                         Pos > 2,
-                                         Pos =< Arity ->
-                                             true;
-                                         true -> false
-                                     end
-                             end,
-                       {bad_type, Tab, {index, [Pos]}})
-        end,
+	fun(Pos) ->
+		verify(
+		  true, fun() ->
+				I = index_pos(Pos),
+				case Pos of
+				    {_, T} ->
+					(T==bag orelse T==ordered)
+					    andalso good_ix_pos(
+						      I, AllowIndexOnKey,
+						      Arity, IxPlugins);
+				    _ ->
+					good_ix_pos(Pos, AllowIndexOnKey,
+						    Arity, IxPlugins)
+				end
+			end,
+		  {bad_type, Tab, {index, [Pos]}})
+	end,
     lists:foreach(IxFun, Index),
 
     LC = Cs#cstruct.local_content,
@@ -926,7 +1223,9 @@ verify_cstruct(Cs) when is_record(Cs, cstruct) ->
 	   {badarg, Tab, {snmp, Snmp}}),
 
     CheckProp = fun(Prop) when is_tuple(Prop), size(Prop) >= 1 -> ok;
-		   (Prop) -> mnesia:abort({bad_type, Tab, {user_properties, [Prop]}})
+		   (Prop) ->
+			mnesia:abort({bad_type, Tab,
+				      {user_properties, [Prop]}})
 		end,
     lists:foreach(CheckProp, Cs#cstruct.user_properties),
 
@@ -946,17 +1245,45 @@ verify_cstruct(Cs) when is_record(Cs, cstruct) ->
             mnesia:abort({bad_type, Tab, {version, Version}})
     end.
 
+good_ix_pos({_} = P, _, _, Plugins) ->
+    lists:keymember(P, 1, Plugins);
+good_ix_pos(I, true, Arity, _) when is_integer(I) ->
+    I >= 0 andalso I =< Arity;
+good_ix_pos(I, false, Arity, _) when is_integer(I) ->
+    I > 2 andalso I =< Arity;
+good_ix_pos(_, _, _, _) ->
+    false.
+
+
+check_if_allow_index_on_key() ->
+    case mnesia_monitor:get_env(allow_index_on_key) of
+	true ->
+	    true;
+	_ ->
+	    false
+    end.
+
 verify_nodes(Cs) ->
     Tab = Cs#cstruct.name,
     Ram = Cs#cstruct.ram_copies,
     Disc = Cs#cstruct.disc_copies,
     DiscOnly = Cs#cstruct.disc_only_copies,
+    Ext = lists:append([Ns || {_,Ns} <- Cs#cstruct.external_copies]),
     LoadOrder = Cs#cstruct.load_order,
 
     verify({alt, [nil, list]}, mnesia_lib:etype(Ram),
 	   {bad_type, Tab, {ram_copies, Ram}}),
     verify({alt, [nil, list]}, mnesia_lib:etype(Disc),
 	   {bad_type, Tab, {disc_copies, Disc}}),
+    lists:foreach(
+      fun({BE, Ns}) ->
+	      verify({alt, [nil, list]}, mnesia_lib:etype(Ns),
+		     {bad_type, Tab, {BE, Ns}}),
+	      lists:foreach(fun(N) ->
+				    verify(atom, mnesia_lib:etype(N),
+					   {bad_type, Tab, {BE, Ns}})
+			    end, Ns)
+      end, Cs#cstruct.external_copies),
     case Tab of
 	schema ->
 	    verify([], DiscOnly, {bad_type, Tab, {disc_only_copies, DiscOnly}});
@@ -968,12 +1295,15 @@ verify_nodes(Cs) ->
     verify(integer, mnesia_lib:etype(LoadOrder),
 	   {bad_type, Tab, {load_order, LoadOrder}}),
 
-    Nodes = Ram ++ Disc ++ DiscOnly,
+    Nodes = Ram ++ Disc ++ DiscOnly ++ Ext,
     verify(list, mnesia_lib:etype(Nodes),
 	   {combine_error, Tab,
-	    [{ram_copies, []}, {disc_copies, []}, {disc_only_copies, []}]}),
+	    [{ram_copies, []}, {disc_copies, []},
+	     {disc_only_copies, []}, {external_copies, []}]}),
     verify(false, has_duplicates(Nodes), {combine_error, Tab, Nodes}),
-    AtomCheck = fun(N) -> verify(atom, mnesia_lib:etype(N), {bad_type, Tab, N}) end,
+    AtomCheck = fun(N) ->
+			verify(atom, mnesia_lib:etype(N), {bad_type, Tab, N})
+		end,
     lists:foreach(AtomCheck, Nodes).
 
 verify(Expected, Fun, Error) when is_function(Fun) ->
@@ -1056,28 +1386,194 @@ check_active([{badrpc, Reason} | _Replies], Expl, Tab) ->
 check_active([], _Expl, _Tab) ->
     ok.
 
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Function for definining an external backend type
+
+add_backend_type(Name, Module) ->
+    case schema_transaction(fun() -> do_add_backend_type(Name, Module) end) of
+	{atomic, NeedsInit} ->
+	    case NeedsInit of
+		true ->
+		    Module:init_backend();
+		false ->
+		    ignore
+	    end,
+	    Module:add_aliases([Name]),
+	    {atomic, ok};
+	Other ->
+	    Other
+    end.
+
+do_add_backend_type(Name, Module) ->
+    verify_backend_type(Name, Module),
+    Types = case do_read_table_property(schema, mnesia_backend_types) of
+		undefined ->
+		    [];
+		{_, Ts} ->
+		    case lists:keymember(Name, 1, Ts) of
+			true ->
+			    mnesia:abort({backend_type_already_exists, Name});
+			false ->
+			    Ts
+		    end
+	    end,
+    ModuleRegistered = lists:keymember(Module, 2, Types),
+    do_write_table_property(schema, {mnesia_backend_types,
+				     [{Name, Module}|Types]}),
+    ModuleRegistered.
+
+delete_backend_type(Name) ->
+    schema_transaction(fun() -> do_delete_backend_type(Name) end).
+
+do_delete_backend_type(Name) ->
+    case do_read_table_property(schema, mnesia_backend_types) of
+	undefined ->
+	    [];
+	{_, Ts} ->
+	    case lists:keyfind(Name, 1, Ts) of
+		{_, Mod} ->
+		    case using_backend_type(Name, Mod) of
+			[_|_] = Tabs ->
+			    mnesia:abort({backend_in_use, {Name, Tabs}});
+			[] ->
+			    do_write_table_property(
+			      schema, {mnesia_backend_types,
+				       lists:keydelete(Name, 1, Ts)})
+		    end;
+		false ->
+		    mnesia:abort({no_such_backend, Name})
+	    end
+    end.
+
+using_backend_type(Name, Mod) ->
+    Ext = ets:select(mnesia_gvar,
+		     [{ {{'$1',external_copies},'$2'}, [], [{{'$1','$2'}}] }]),
+    Entry = {Name, Mod},
+    [T || {T,C} <- Ext,
+	  lists:keymember(Entry, 1, C)].
+
+verify_backend_type(Name, Module) ->
+    case legal_backend_name(Name) of
+	false ->
+	    mnesia:abort({bad_type, {backend_type,Name,Module}});
+	true ->
+	    ok
+    end,
+    ExpectedExports = mnesia_backend_type:behaviour_info(callbacks),
+    Exports = try Module:module_info(exports)
+              catch
+                  error:_ ->
+                      mnesia:abort({undef_backend, Module})
+              end,
+    case ExpectedExports -- Exports of
+        [] ->
+	    ok;
+        _Other ->
+	    io:fwrite(user, "Missing backend_type exports: ~p~n", [_Other]),
+            mnesia:abort({bad_type, {backend_type,Name,Module}})
+    end.
+
+legal_backend_name(Name) ->
+    is_atom(Name) andalso
+                    (not lists:member(Name, record_info(fields, cstruct))).
+
+%% Used e.g. by mnesia:system_info(backend_types).
+backend_types() ->
+    [ram_copies, disc_copies, disc_only_copies |
+     [T || {T,_} <- get_ext_types()]].
+
+add_index_plugin(Name, Module, Function) ->
+    schema_transaction(
+      fun() -> do_add_index_plugin(Name, Module, Function) end).
+
+do_add_index_plugin(Name, Module, Function) ->
+    verify_index_plugin(Name, Module, Function),
+    Plugins = case do_read_table_property(schema, mnesia_index_plugins) of
+		  undefined ->
+		      [];
+		  {_, Ps} ->
+		      case lists:keymember(Name, 1, Ps) of
+			  true ->
+			      mnesia:abort({index_plugin_already_exists, Name});
+			  false ->
+			      Ps
+		      end
+	      end,
+    do_write_table_property(schema, {mnesia_index_plugins,
+				     [{Name, Module, Function}|Plugins]}).
+
+delete_index_plugin(P) ->
+    schema_transaction(
+      fun() -> do_delete_index_plugin(P) end).
+
+do_delete_index_plugin({A} = P) when is_atom(A) ->
+    Plugins = get_index_plugins(),
+    case lists:keyfind(P, 1, Plugins) of
+	false ->
+	    mnesia:abort({no_exists, {index_plugin, P}});
+	_Found ->
+	    case ets:select(mnesia_gvar,
+			    [{ {{'$1',{index,{P,'_'}}},'_'},[],['$1']},
+			     { {{'$1',{index,P}},'_'},[],['$1']}], 1) of
+		{[_], _} ->
+		    mnesia:abort({plugin_in_use, P});
+		'$end_of_table' ->
+		    do_write_table_property(
+		      schema, {mnesia_index_plugins,
+			       lists:keydelete(P, 1, Plugins)})
+	    end
+    end.
+
+verify_index_plugin({A} = Name, Module, Function)
+  when is_atom(A), is_atom(Module), is_atom(Function) ->
+    case code:ensure_loaded(Module) of
+	{error, nofile} ->
+	    mnesia:abort({bad_type, {index_plugin,Name,Module,Function}});
+	{module,_} ->
+	    %% Index plugins are called as Module:Function(Tab, Pos, Obj)
+	    case erlang:function_exported(Module, Function, 3) of
+		true ->
+		    ok;
+		false ->
+		    mnesia:abort(
+		      {bad_type, {index_plugin,Name,Module,Function}})
+	    end
+    end;
+verify_index_plugin(Name, Module, Function) ->
+    mnesia:abort({bad_type, {index_plugin,Name,Module,Function}}).
+
+
+%% Used e.g. by mnesia:system_info(backend_types).
+index_plugins() ->
+    get_index_plugins().
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Here's the real interface function to create a table
 
-create_table(TabDef) ->
-    schema_transaction(fun() -> do_multi_create_table(TabDef) end).
+create_table([_|_] = TabDef) ->
+    schema_transaction(fun() -> do_multi_create_table(TabDef) end);
+create_table(Arg) -> {aborted, {badarg, Arg}}.
 
 %% And the corresponding do routines ....
 
 do_multi_create_table(TabDef) ->
     get_tid_ts_and_lock(schema, write),
     ensure_writable(schema),
+    do_create_table(TabDef),
+    ok.
+
+do_create_table(TabDef) when is_list(TabDef) ->
     Cs = api_list2cs(TabDef),
     case Cs#cstruct.frag_properties of
 	[] ->
-	    do_create_table(Cs);
+	    do_create_table_1(Cs);
 	_Props ->
 	    CsList = mnesia_frag:expand_cstruct(Cs),
-	    lists:foreach(fun do_create_table/1, CsList)
-    end,
-    ok.
+	    lists:foreach(fun do_create_table_1/1, CsList)
+    end.
 
-do_create_table(Cs) ->
+do_create_table_1(Cs) ->
     {_Mod, _Tid, Ts} =  get_tid_ts_and_lock(schema, none),
     Store = Ts#tidstore.store,
     do_insert_schema_ops(Store, make_create_table(Cs)).
@@ -1087,14 +1583,9 @@ make_create_table(Cs) ->
     verify(false, check_if_exists(Tab), {already_exists, Tab}),
     unsafe_make_create_table(Cs).
 
-% unsafe_do_create_table(Cs) ->
-%     {_Mod, Tid, Ts} =  get_tid_ts_and_lock(schema, none),
-%     Store = Ts#tidstore.store,
-%     do_insert_schema_ops(Store, unsafe_make_create_table(Cs)).
-
-unsafe_make_create_table(Cs) ->
+unsafe_make_create_table(Cs0) ->
     {_Mod, Tid, Ts} =  get_tid_ts_and_lock(schema, none),
-    verify_cstruct(Cs),
+    Cs = verify_cstruct(Cs0),
     Tab = Cs#cstruct.name,
 
     %% Check that we have all disc replica nodes running
@@ -1141,6 +1632,7 @@ do_delete_table(Tab) ->
     ensure_writable(schema),
     insert_schema_ops(TidTs, make_delete_table(Tab, whole_table)).
 
+-dialyzer({no_improper_lists, make_delete_table/2}).
 make_delete_table(Tab, Mode) ->
     case existed_before(Tab) of
 	false ->
@@ -1241,8 +1733,7 @@ make_add_table_copy(Tab, Node, Storage) ->
     Cs = incr_version(val({Tab, cstruct})),
     Ns = mnesia_lib:cs_to_nodes(Cs),
     verify(false, lists:member(Node, Ns), {already_exists, Tab, Node}),
-    Cs2 = new_cs(Cs, Node, Storage, add),
-    verify_cstruct(Cs2),
+    Cs2 = verify_cstruct(new_cs(Cs, Node, Storage, add)),
 
     %% Check storage and if node is running
     IsRunning = lists:member(Node, val({current, db_nodes})),
@@ -1290,13 +1781,14 @@ make_del_table_copy(Tab, Node) ->
         _ when Tab == schema ->
 	    %% ensure_active(Cs2),
 	    ensure_not_active(Tab, Node),
-            verify_cstruct(Cs2),
+            Cs3 = verify_cstruct(Cs2),
 	    Ops = remove_node_from_tabs(val({schema, tables}), Node),
-	    [{op, del_table_copy, ram_copies, Node, vsn_cs2list(Cs2)} | Ops];
+	    [{op, del_table_copy, ram_copies, Node, vsn_cs2list(Cs3)} | Ops];
         _ ->
 	    ensure_active(Cs),
-            verify_cstruct(Cs2),
-            [{op, del_table_copy, Storage, Node, vsn_cs2list(Cs2)}]
+            Cs3 = verify_cstruct(Cs2),
+            get_tid_ts_and_lock(Tab, write),
+            [{op, del_table_copy, Storage, Node, vsn_cs2list(Cs3)}]
     end.
 
 remove_node_from_tabs([], _Node) ->
@@ -1322,8 +1814,9 @@ remove_node_from_tabs([Tab|Rest], Node) ->
 		    [{op, delete_table, vsn_cs2list(Cs)} |
 		     remove_node_from_tabs(Rest, Node)];
 		_Ns ->
-		    verify_cstruct(Cs2),
-		    [{op, del_table_copy, ram_copies, Node, vsn_cs2list(Cs2)}|
+		    Cs3 = verify_cstruct(Cs2),
+		    get_tid_ts_and_lock(Tab, write),
+		    [{op, del_table_copy, ram_copies, Node, vsn_cs2list(Cs3)}|
 		     remove_node_from_tabs(Rest, Node)]
 	    end
     end.
@@ -1341,8 +1834,34 @@ new_cs(Cs, Node, disc_copies, del) ->
 new_cs(Cs, Node, disc_only_copies, del) ->
     Cs#cstruct{disc_only_copies =
                lists:delete(Node , Cs#cstruct.disc_only_copies)};
-new_cs(Cs, _Node, Storage, _Op) ->
-    mnesia:abort({badarg, Cs#cstruct.name, Storage}).
+new_cs(#cstruct{external_copies = ExtCps} = Cs, Node, Storage0, Op) ->
+    Storage = case Storage0 of
+		  {ext, Alias, _} -> Alias;
+		  Alias -> Alias
+	      end,
+    ExtTypes = get_ext_types(),
+    case lists:keyfind(Storage, 1, ExtTypes) of
+	false ->
+	    mnesia:abort({badarg, Cs#cstruct.name, Storage});
+	{_, Mod} ->
+	    Key = {Storage, Mod},
+	    case {lists:keymember(Key, 1, ExtCps), Op} of
+		{false, del} ->
+		    Cs;
+		{false, add} ->
+		    Cs#cstruct{external_copies = [{Key, [Node]}|ExtCps]};
+		{true, _} ->
+		    F = fun({K, Ns}) when K == Key ->
+				case Op of
+				    del -> {K, lists:delete(Node, Ns)};
+				    add -> {K, opt_add(Node, Ns)}
+				end;
+			   (X) ->
+				X
+			end,
+		    Cs#cstruct{external_copies = lists:map(F, ExtCps)}
+	    end
+    end.
 
 
 opt_add(N, L) -> [N | lists:delete(N, L)].
@@ -1354,6 +1873,11 @@ do_move_table(schema, _FromNode, _ToNode) ->
     mnesia:abort({bad_type, schema});
 do_move_table(Tab, FromNode, ToNode) when is_atom(FromNode), is_atom(ToNode) ->
     TidTs = get_tid_ts_and_lock(schema, write),
+    AnyOld = lists:any(fun(Node) -> mnesia_monitor:needs_protocol_conversion(Node) end,
+		       [ToNode|val({Tab, where_to_write})]),
+    if AnyOld -> ignore;  %% Leads to deadlock on old nodes
+       true -> get_tid_ts_and_lock(Tab, write)
+    end,
     insert_schema_ops(TidTs, make_move_table(Tab, FromNode, ToNode));
 do_move_table(Tab, FromNode, ToNode) ->
     mnesia:abort({badarg, Tab, FromNode, ToNode}).
@@ -1373,8 +1897,7 @@ make_move_table(Tab, FromNode, ToNode) ->
     verify(true, lists:member(ToNode, Running), {not_active, schema, ToNode}),
 
     Cs2 = new_cs(Cs, ToNode, Storage, add),
-    Cs3 = new_cs(Cs2, FromNode, Storage, del),
-    verify_cstruct(Cs3),
+    Cs3 = verify_cstruct(new_cs(Cs2, FromNode, Storage, del)),
     [{op, add_table_copy, Storage, ToNode, vsn_cs2list(Cs2)},
      {op, sync_trans},
      {op, del_table_copy, Storage, FromNode, vsn_cs2list(Cs3)}].
@@ -1401,9 +1924,11 @@ make_change_table_copy_type(Tab, Node, ToS) ->
     Cs = incr_version(val({Tab, cstruct})),
     FromS = mnesia_lib:storage_type_at_node(Node, Tab),
 
-    case compare_storage_type(false, FromS, ToS) of
+    ToSExp = expand_storage_type(ToS),
+
+    case compare_storage_type(false, FromS, ToSExp) of
 	{same, _} ->
-	    mnesia:abort({already_exists, Tab, Node, ToS});
+	    mnesia:abort({already_exists, Tab, Node, ToSExp});
 	{diff, _} ->
 	    ignore;
 	incompatible ->
@@ -1411,10 +1936,8 @@ make_change_table_copy_type(Tab, Node, ToS) ->
     end,
 
     Cs2 = new_cs(Cs, Node, FromS, del),
-    Cs3 = new_cs(Cs2, Node, ToS, add),
-    verify_cstruct(Cs3),
-
-    [{op, change_table_copy_type, Node, FromS, ToS, vsn_cs2list(Cs3)}].
+    Cs3 = verify_cstruct(new_cs(Cs2, Node, ToS, add)),
+    [{op, change_table_copy_type, Node, FromS, ToSExp, vsn_cs2list(Cs3)}].
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% change index functions ....
@@ -1436,11 +1959,12 @@ make_add_table_index(Tab, Pos) ->
     Cs = incr_version(val({Tab, cstruct})),
     ensure_active(Cs),
     Ix = Cs#cstruct.index,
-    verify(false, lists:member(Pos, Ix), {already_exists, Tab, Pos}),
+    verify(false, lists:keymember(index_pos(Pos), 1, Ix),
+	   {already_exists, Tab, Pos}),
     Ix2 = lists:sort([Pos | Ix]),
-    Cs2 = Cs#cstruct{index = Ix2},
-    verify_cstruct(Cs2),
-    [{op, add_index, Pos, vsn_cs2list(Cs2)}].
+    Cs2 = verify_cstruct(Cs#cstruct{index = Ix2}),
+    NewPosInfo = lists:keyfind(Pos, 1, Cs2#cstruct.index),
+    [{op, add_index, NewPosInfo, vsn_cs2list(Cs2)}].
 
 del_table_index(Tab, Pos) ->
     schema_transaction(fun() -> do_del_table_index(Tab, Pos) end).
@@ -1458,9 +1982,8 @@ make_del_table_index(Tab, Pos) ->
     Cs = incr_version(val({Tab, cstruct})),
     ensure_active(Cs),
     Ix = Cs#cstruct.index,
-    verify(true, lists:member(Pos, Ix), {no_exists, Tab, Pos}),
-    Cs2 = Cs#cstruct{index = lists:delete(Pos, Ix)},
-    verify_cstruct(Cs2),
+    verify(true, lists:keymember(Pos, 1, Ix), {no_exists, Tab, Pos}),
+    Cs2 = verify_cstruct(Cs#cstruct{index = lists:keydelete(Pos, 1, Ix)}),
     [{op, del_index, Pos, vsn_cs2list(Cs2)}].
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -1482,8 +2005,7 @@ make_add_snmp(Tab, Ustruct) ->
     verify([], Cs#cstruct.snmp, {already_exists, Tab, snmp}),
     Error = {badarg, Tab, snmp, Ustruct},
     verify(true, mnesia_snmp_hook:check_ustruct(Ustruct), Error),
-    Cs2 = Cs#cstruct{snmp = Ustruct},
-    verify_cstruct(Cs2),
+    Cs2 = verify_cstruct(Cs#cstruct{snmp = Ustruct}),
     [{op, add_snmp, Ustruct, vsn_cs2list(Cs2)}].
 
 del_snmp(Tab) ->
@@ -1500,8 +2022,7 @@ make_del_snmp(Tab) ->
     ensure_writable(schema),
     Cs = incr_version(val({Tab, cstruct})),
     ensure_active(Cs),
-    Cs2 = Cs#cstruct{snmp = []},
-    verify_cstruct(Cs2),
+    Cs2 = verify_cstruct(Cs#cstruct{snmp = []}),
     [{op, del_snmp, vsn_cs2list(Cs2)}].
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -1530,19 +2051,21 @@ make_transform(Tab, Fun, NewAttrs, NewRecName) ->
     Cs = incr_version(val({Tab, cstruct})),
     ensure_active(Cs),
     ensure_writable(Tab),
-    case mnesia_lib:val({Tab, index}) of
+    case Cs#cstruct.index of
 	[] ->
-	    Cs2 = Cs#cstruct{attributes = NewAttrs, record_name = NewRecName},
-	    verify_cstruct(Cs2),
+	    Cs2 = verify_cstruct(
+                    Cs#cstruct{attributes = NewAttrs,
+                               record_name = NewRecName}),
 	    [{op, transform, Fun, vsn_cs2list(Cs2)}];
 	PosList ->
-	    DelIdx = fun(Pos, Ncs) ->
+	    DelIdx = fun({Pos,_}, Ncs) ->
 			     Ix = Ncs#cstruct.index,
-			     Ncs1 = Ncs#cstruct{index = lists:delete(Pos, Ix)},
+			     Ix2 = lists:keydelete(Pos, 1, Ix),
+			     Ncs1 = Ncs#cstruct{index = Ix2},
 			     Op = {op, del_index, Pos, vsn_cs2list(Ncs1)},
 			     {Op, Ncs1}
 		     end,
-	    AddIdx = fun(Pos, Ncs) ->
+	    AddIdx = fun({_,_} = Pos, Ncs) ->
 			     Ix = Ncs#cstruct.index,
 			     Ix2 = lists:sort([Pos | Ix]),
 			     Ncs1 = Ncs#cstruct{index = Ix2},
@@ -1552,10 +2075,16 @@ make_transform(Tab, Fun, NewAttrs, NewRecName) ->
             {DelOps, Cs1} = lists:mapfoldl(DelIdx, Cs, PosList),
 	    Cs2 = Cs1#cstruct{attributes = NewAttrs, record_name = NewRecName},
             {AddOps, Cs3} = lists:mapfoldl(AddIdx, Cs2, PosList),
-	    verify_cstruct(Cs3),
-	    lists:flatten([DelOps, {op, transform, Fun, vsn_cs2list(Cs2)}, AddOps])
+	    _ = verify_cstruct(Cs3), % just a sanity check
+	    lists:flatten([DelOps, {op, transform, Fun, vsn_cs2list(Cs2)},
+			   AddOps])
     end.
 
+index_pos({Pos,_}) -> Pos;
+index_pos(Pos) when is_integer(Pos) -> Pos;
+index_pos({P} = Pos) when is_atom(P) -> Pos.
+
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%
 
@@ -1575,8 +2104,7 @@ make_change_table_access_mode(Tab, Mode) ->
     ensure_active(Cs),
     OldMode = Cs#cstruct.access_mode,
     verify(false, OldMode ==  Mode, {already_exists, Tab, Mode}),
-    Cs2 = Cs#cstruct{access_mode = Mode},
-    verify_cstruct(Cs2),
+    Cs2 = verify_cstruct(Cs#cstruct{access_mode = Mode}),
     [{op, change_table_access_mode, vsn_cs2list(Cs2), OldMode, Mode}].
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -1596,8 +2124,7 @@ make_change_table_load_order(Tab, LoadOrder) ->
     Cs = incr_version(val({Tab, cstruct})),
     ensure_active(Cs),
     OldLoadOrder = Cs#cstruct.load_order,
-    Cs2 = Cs#cstruct{load_order = LoadOrder},
-    verify_cstruct(Cs2),
+    Cs2 = verify_cstruct(Cs#cstruct{load_order = LoadOrder}),
     [{op, change_table_load_order, vsn_cs2list(Cs2), OldLoadOrder, LoadOrder}].
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -1643,6 +2170,7 @@ write_table_property(Tab, Prop) when is_tuple(Prop), size(Prop) >= 1 ->
     schema_transaction(fun() -> do_write_table_property(Tab, Prop) end);
 write_table_property(Tab, Prop) ->
     {aborted, {bad_type, Tab, Prop}}.
+
 do_write_table_property(Tab, Prop) ->
     TidTs = get_tid_ts_and_lock(schema, write),
     {_, _, Ts} = TidTs,
@@ -1674,8 +2202,7 @@ make_write_table_properties(Tab, [Prop | Props], Cs) ->
     PropKey = element(1, Prop),
     DelProps = lists:keydelete(PropKey, 1, OldProps),
     MergedProps = lists:merge(DelProps, [Prop]),
-    Cs2 = Cs#cstruct{user_properties = MergedProps},
-    verify_cstruct(Cs2),
+    Cs2 = verify_cstruct(Cs#cstruct{user_properties = MergedProps}),
     [{op, write_property, vsn_cs2list(Cs2), Prop} |
      make_write_table_properties(Tab, Props, Cs2)];
 make_write_table_properties(_Tab, [], _Cs) ->
@@ -1720,22 +2247,38 @@ do_read_table_property(Tab, Key) ->
     {_, _, Ts} = TidTs,
     Store = Ts#tidstore.store,
     Props = ets:foldl(
-	      fun({op, create_table, [{name, T}|Opts]}, _Acc)
-		 when T==Tab ->
+	      fun({op, announce_im_running,_,Opts,_,_}, _Acc) when Tab==schema ->
+		      find_props(Opts);
+		 ({op, create_table, [{name, T}|Opts]}, _Acc)
+		    when T==Tab ->
 		      find_props(Opts);
 		 ({op, Op, [{name,T}|Opts], _Prop}, _Acc)
-		 when T==Tab, Op==write_property; Op==delete_property ->
+		 when T==Tab, Op==write_property;
+		      T==Tab, Op==delete_property ->
 		      find_props(Opts);
 		 ({op, delete_table, [{name,T}|_]}, _Acc)
 		 when T==Tab ->
 		      [];
 		 (_Other, Acc) ->
 		      Acc
-	      end, [], Store),
-    case lists:keysearch(Key, 1, Props) of
-	{value, Property} ->
-	    Property;
-	false ->
+	      end, undefined, Store),
+    case Props of
+        undefined ->
+            get_tid_ts_and_lock(Tab, read),
+	    dirty_read_table_property(Tab, Key);
+        _ when is_list(Props) ->
+            case lists:keyfind(Key, 1, Props) of
+		false ->
+		    undefined;
+		Other ->
+		    Other
+            end
+    end.
+
+dirty_read_table_property(Tab, Key) ->
+    try ets:lookup_element(mnesia_gvar, {Tab,user_property,Key}, 2)
+    catch
+	error:_ ->
 	    undefined
     end.
 
@@ -1795,8 +2338,7 @@ make_delete_table_properties(Tab, PropKeys) ->
 make_delete_table_properties(Tab, [PropKey | PropKeys], Cs) ->
     OldProps = Cs#cstruct.user_properties,
     Props = lists:keydelete(PropKey, 1, OldProps),
-    Cs2 = Cs#cstruct{user_properties = Props},
-    verify_cstruct(Cs2),
+    Cs2 = verify_cstruct(Cs#cstruct{user_properties = Props}),
     [{op, delete_property, vsn_cs2list(Cs2), PropKey} |
      make_delete_table_properties(Tab, PropKeys, Cs2)];
 make_delete_table_properties(_Tab, [], _Cs) ->
@@ -1937,6 +2479,11 @@ prepare_op(Tid, {op, create_table, TabDef}, _WaitFor) ->
 	    create_disc_only_table(Tab,Cs),
 	    insert_cstruct(Tid, Cs, false),
 	    {true, optional};
+	{ext, Alias, Mod} ->
+	    mnesia_lib:set({Tab, create_table},true),
+            create_external_table(Alias, Tab, Mod, Cs),
+	    insert_cstruct(Tid, Cs, false),
+	    {true, optional};
         unknown -> %% No replica on this node
 	    mnesia_lib:set({Tab, create_table},true),
 	    insert_cstruct(Tid, Cs, false),
@@ -1961,7 +2508,7 @@ prepare_op(Tid, {op, add_table_copy, Storage, Node, TabDef}, _WaitFor) ->
 	    end,
 	    %% Tables are created by mnesia_loader get_network code
 	    insert_cstruct(Tid, Cs, true),
-	    case mnesia_controller:get_network_copy(Tab, Cs) of
+	    case mnesia_controller:get_network_copy(Tid, Tab, Cs) of
 		{loaded, ok} ->
 		    {true, optional};
 		{not_loaded, ErrReason} ->
@@ -1992,28 +2539,11 @@ prepare_op(Tid, {op, add_table_copy, Storage, Node, TabDef}, _WaitFor) ->
 	    {true, optional}
     end;
 
-prepare_op(Tid, {op, del_table_copy, _Storage, Node, TabDef}, _WaitFor) ->
+prepare_op(_Tid, {op, del_table_copy, _Storage, Node, TabDef}, _WaitFor) ->
     Cs = list2cs(TabDef),
     Tab = Cs#cstruct.name,
-
-    if
-	%% Schema table lock is always required to run a schema op.
-	%% No need to look it.
-	node(Tid#tid.pid) == node(), Tab /= schema ->
-	    Self = self(),
-	    Pid = spawn_link(fun() -> lock_del_table(Tab, Node, Cs, Self) end),
-	    put(mnesia_lock, Pid),
-	    receive
-		{Pid, updated} ->
-		    {true, optional};
-		{Pid, FailReason} ->
-		    mnesia:abort(FailReason);
-		{'EXIT', Pid, Reason} ->
-		    mnesia:abort(Reason)
-	    end;
-	true ->
-	    {true, optional}
-    end;
+    set_where_to_read(Tab, Node, Cs),
+    {true, optional};
 
 prepare_op(_Tid, {op, change_table_copy_type,  N, FromS, ToS, TabDef}, _WaitFor)
   when N == node() ->
@@ -2022,6 +2552,12 @@ prepare_op(_Tid, {op, change_table_copy_type,  N, FromS, ToS, TabDef}, _WaitFor)
 
     NotActive = mnesia_lib:not_active_here(Tab),
 
+    if Tab =/= schema ->
+	    check_if_disc_required(FromS, ToS);
+       true ->
+	    ok
+    end,
+
     if
 	NotActive == true ->
 	    mnesia:abort({not_active, Tab, node()});
@@ -2061,6 +2597,15 @@ prepare_op(_Tid, {op, change_table_copy_type,  N, FromS, ToS, TabDef}, _WaitFor)
 		    mnesia:abort({combine_error, Tab, ToS})
 	    end;
 
+	element(1,FromS) == ext; element(1,ToS) == ext ->
+	    if ToS == ram_copies ->
+		    create_ram_table(Tab, Cs);
+	       true ->
+		    ok
+	    end,
+            mnesia_dumper:dump_to_logfile(FromS, Tab),
+            mnesia_checkpoint:tm_change_table_copy_type(Tab, FromS, ToS);
+
 	FromS == ram_copies ->
 	    case mnesia_monitor:use_dir() of
 		true ->
@@ -2076,7 +2621,9 @@ prepare_op(_Tid, {op, change_table_copy_type,  N, FromS, ToS, TabDef}, _WaitFor)
 				disc_only_copies ->
 				    mnesia_dumper:raw_named_dump_table(Tab, dmp)
 			    end,
-			    mnesia_checkpoint:tm_change_table_copy_type(Tab, FromS, ToS)
+			    mnesia_checkpoint:tm_change_table_copy_type(Tab,
+                                                                        FromS,
+                                                                        ToS)
 		    end;
 		false ->
 		    mnesia:abort({has_no_disc, node()})
@@ -2084,6 +2631,7 @@ prepare_op(_Tid, {op, change_table_copy_type,  N, FromS, ToS, TabDef}, _WaitFor)
 
 	FromS == disc_copies, ToS == disc_only_copies ->
 	    mnesia_dumper:raw_named_dump_table(Tab, dmp);
+
 	FromS == disc_only_copies ->
 	    Type = Cs#cstruct.type,
 	    create_ram_table(Tab, Cs),
@@ -2095,6 +2643,7 @@ prepare_op(_Tid, {op, change_table_copy_type,  N, FromS, ToS, TabDef}, _WaitFor)
 		    Err = "Failed to copy disc data to ram",
 		    mnesia:abort({system_limit, Tab, {Err,Reason}})
 	    end;
+
 	true ->
 	    ignore
     end,
@@ -2151,14 +2700,16 @@ prepare_op(_Tid, {op, transform, Fun, TabDef}, _WaitFor) ->
 	    mnesia_lib:db_fixtable(Storage, Tab, true),
             Key = mnesia_lib:db_first(Tab),
 	    Op = {op, transform, Fun, TabDef},
-            case catch transform_objs(Fun, Tab, RecName,
-				      Key, NewArity, Storage, Type, [Op]) of
-                {'EXIT', Reason} ->
-		    mnesia_lib:db_fixtable(Storage, Tab, false),
-                    exit({"Bad transform function", Tab, Fun, node(), Reason});
+            try transform_objs(Fun, Tab, RecName, Key,
+			       NewArity, Storage, Type, [Op]) of
                 Objs ->
 		    mnesia_lib:db_fixtable(Storage, Tab, false),
                     {true, Objs, mandatory}
+	    catch _:Reason ->
+		    mnesia_lib:db_fixtable(Storage, Tab, false),
+		    mnesia_lib:important("Transform function failed: '~p' in '~p'",
+					 [Reason, erlang:get_stacktrace()]),
+                    exit({"Bad transform function", Tab, Fun, node(), Reason})
             end
     end;
 
@@ -2174,6 +2725,22 @@ prepare_op(_Tid, {op, merge_schema, TabDef}, _WaitFor) ->
 prepare_op(_Tid, _Op, _WaitFor) ->
     {true, optional}.
 
+check_if_disc_required(FromS, ToS) ->
+    FromSem = mnesia_lib:semantics(FromS, storage),
+    ToSem = mnesia_lib:semantics(ToS, storage),
+    case {FromSem, ToSem} of
+	{ram_copies, _} when ToSem == disc_copies;
+			     ToSem == disc_only_copies ->
+	    case mnesia_monitor:use_dir() of
+		true ->
+		    ok;
+		false ->
+		    mnesia:abort({has_no_disc, node()})
+	    end;
+	_ ->
+	    ok
+    end.
+
 create_ram_table(Tab, #cstruct{type=Type, storage_properties=Props}) ->
     EtsOpts = proplists:get_value(ets, Props, []),
     Args = [{keypos, 2}, public, named_table, Type | EtsOpts],
@@ -2215,6 +2782,14 @@ create_disc_only_table(Tab, #cstruct{type=Type, storage_properties=Props}) ->
 	    mnesia:abort({system_limit, Tab, {Err,Reason}})
     end.
 
+create_external_table(Alias, Tab, Mod, Cs) ->
+    case mnesia_monitor:unsafe_create_external(Tab, Alias, Mod, Cs) of
+	ok ->
+	    ok;
+	{error,Reason} ->
+	    Err = "Failed to create external table",
+	    mnesia:abort({system_limit, Tab, {Err,Reason}})
+    end.
 
 receive_sync([], Pids) ->
     Pids;
@@ -2227,46 +2802,6 @@ receive_sync(Nodes, Pids) ->
 	    {abort, Else}
     end.
 
-lock_del_table(Tab, NewNode, Cs0, Father) ->
-    Ns = val({schema, active_replicas}),
-    process_flag(trap_exit,true),
-    Lock = fun() ->
-		   mnesia:write_lock_table(Tab),
-		   %% Sigh using cs record
-		   Set = fun(Node) ->
-				 [Cs] = normalize_cs([Cs0], Node),
-				 rpc:call(Node, ?MODULE, set_where_to_read, [Tab, NewNode, Cs])
-			 end,
-		   Res = [Set(Node) || Node <- Ns],
-		   Filter = fun(ok) ->
-				    false;
-			       ({badrpc, {'EXIT', {undef, _}}}) ->
-				    %% This will be the case we talks with elder nodes
-				    %% than 3.8.2, they will set where_to_read without
-				    %% getting a lock.
-				    false;
-			       (_) ->
-				    true
-			    end,
-		   case lists:filter(Filter, Res) of
-		       [] ->
-			   Father ! {self(), updated},
-			   %% When transaction is commited the process dies
-			   %% and the lock is released.
-			   receive _ -> ok end;
-		       Err ->
-			   Father ! {self(), {bad_commit, Err}}
-		   end,
-		   ok
-	   end,
-    case mnesia:transaction(Lock) of
-	{atomic, ok} ->  ok;
-	{aborted, R} ->  Father ! {self(), R}
-    end,
-    unlink(Father),
-    unlink(whereis(mnesia_tm)),
-    exit(normal).
-
 set_where_to_read(Tab, Node, Cs) ->
     case mnesia_lib:val({Tab, where_to_read}) of
 	Node ->
@@ -2342,7 +2877,7 @@ undo_prepare_commit(Tid, Commit) ->
 	    ignore;
 	Ops ->
 	    %% Catch to allow failure mnesia_controller may not be started
-	    catch mnesia_controller:release_schema_commit_lock(),
+	    ?SAFE(mnesia_controller:release_schema_commit_lock()),
 	    undo_prepare_ops(Tid, Ops)
     end,
     Commit.
@@ -2389,7 +2924,10 @@ undo_prepare_op(Tid, {op, create_table, TabDef}) ->
 	    mnesia_monitor:unsafe_close_dets(Tab),
 	    Dat = mnesia_lib:tab2dat(Tab),
 	    %%	    disc_delete_table(Tab, Storage),
-	    file:delete(Dat)
+	    file:delete(Dat);
+        {ext, Alias, Mod} ->
+	    Mod:close_table(Alias, Tab),
+            Mod:delete_table(Alias, Tab)
     end;
 
 undo_prepare_op(Tid, {op, add_table_copy, Storage, Node, TabDef}) ->
@@ -2417,13 +2955,19 @@ undo_prepare_op(Tid, {op, add_table_copy, Storage, Node, TabDef}) ->
 	    insert_cstruct(Tid, Cs2, true) % Don't care about the version
     end;
 
-undo_prepare_op(_Tid, {op, del_table_copy, _, Node, TabDef})
-  when Node == node() ->
-    WriteLocker = get(mnesia_lock),
-    WriteLocker =/= undefined andalso (WriteLocker ! die),
+undo_prepare_op(_Tid, {op, del_table_copy, _, Node, TabDef}) ->
     Cs = list2cs(TabDef),
     Tab = Cs#cstruct.name,
-    mnesia_lib:set({Tab, where_to_read}, Node);
+    if node() =:= Node ->
+	    mnesia_lib:set({Tab, where_to_read}, Node);
+       true ->
+	    case mnesia_lib:val({Tab, where_to_read}) of
+		nowhere ->
+		    mnesia_lib:set_remote_where_to_read(Tab);
+		_ ->
+		    ignore
+	    end
+    end;
 
 undo_prepare_op(_Tid, {op, change_table_copy_type, N, FromS, ToS, TabDef})
         when N == node() ->
@@ -2483,20 +3027,22 @@ ram_delete_table(Tab, Storage) ->
     case Storage of
 	unknown ->
 	    ignore;
+        {ext, _, _} ->
+            ignore;
 	disc_only_copies ->
 	    ignore;
 	_Else ->
 	    %% delete possible index files and data .....
 	    %% Got to catch this since if no info has been set in the
 	    %% mnesia_gvar it will crash
-	    catch mnesia_index:del_transient(Tab, Storage),
+	    ?CATCH(mnesia_index:del_transient(Tab, Storage)),
 	    case ?catch_val({Tab, {index, snmp}}) of
 		{'EXIT', _} ->
 		    ignore;
 		Etab ->
-		    catch mnesia_snmp_hook:delete_table(Tab, Etab)
+		    ?SAFE(mnesia_snmp_hook:delete_table(Tab, Etab))
 	    end,
-	    catch ?ets_delete_table(Tab)
+	    ?SAFE(?ets_delete_table(Tab))
     end.
 
 purge_dir(Dir, KeepFiles) ->
@@ -2544,13 +3090,27 @@ purge_known_files([File | Tail], KeepFiles, Dir, Suffixes) ->
 		    ignore;
 		true ->
 		    AbsFile = filename:join([Dir, File]),
-		    file:delete(AbsFile)
-	    end
+                    delete_recursive(AbsFile)
+            end
     end,
     purge_known_files(Tail, KeepFiles, Dir, Suffixes);
 purge_known_files([], _KeepFiles, _Dir, _Suffixes) ->
     ok.
 
+%% Removes a directory or file recursively
+delete_recursive(Path) ->
+    case filelib:is_dir(Path) of
+        true ->
+            {ok, Names} = file:list_dir(Path),
+            lists:foreach(fun(Name) ->
+                                  delete_recursive(filename:join(Path, Name))
+                          end,
+                          Names),
+            file:del_dir(Path);
+        false ->
+            file:delete(Path)
+    end.
+
 has_known_suffix(_File, _Suffixes, true) ->
     true;
 has_known_suffix(File, [Suffix | Tail], false) ->
@@ -2558,11 +3118,33 @@ has_known_suffix(File, [Suffix | Tail], false) ->
 has_known_suffix(_File, [], Bool) ->
     Bool.
 
-known_suffixes() -> real_suffixes() ++ tmp_suffixes().
+known_suffixes() -> known_suffixes(get_ext_types_disc()).
 
-real_suffixes() ->  [".DAT", ".LOG", ".BUP", ".DCL", ".DCD"].
+known_suffixes(Ext) -> real_suffixes(Ext) ++ tmp_suffixes(Ext).
 
-tmp_suffixes() -> [".TMP", ".BUPTMP", ".RET", ".DMP"].
+real_suffixes(Ext) ->  [".DAT", ".LOG", ".BUP", ".DCL", ".DCD"] ++ ext_real_suffixes(Ext).
+
+tmp_suffixes() -> tmp_suffixes(get_ext_types_disc()).
+
+tmp_suffixes(Ext) -> [".TMP", ".BUPTMP", ".RET", ".DMP", "."] ++ ext_tmp_suffixes(Ext).
+
+ext_real_suffixes(Ext) ->
+    try lists:foldl(fun(Mod, Acc) -> Acc++Mod:real_suffixes() end, [],
+		    [M || {_,M} <- Ext])
+    catch
+        error:E ->
+            verbose("Cant find real ext suffixes (~p)~n", [E]),
+            []
+    end.
+
+ext_tmp_suffixes(Ext) ->
+    try lists:foldl(fun(Mod, Acc) -> Acc++Mod:tmp_suffixes() end, [],
+		    [M || {_,M} <- Ext])
+    catch
+        error:E ->
+            verbose("Cant find tmp ext suffixes (~p)~n", [E]),
+            []
+    end.
 
 info() ->
     Tabs = lists:sort(val({schema, tables})),
@@ -2584,10 +3166,7 @@ info2(_, []) ->
     io:format("~n", []).
 
 get_table_properties(Tab) ->
-    case catch mnesia_lib:db_match_object(ram_copies,
-					  mnesia_gvar, {{Tab, '_'}, '_'}) of
-	{'EXIT', _} ->
-	    mnesia:abort({no_exists, Tab, all});
+    try mnesia_lib:db_match_object(ram_copies, mnesia_gvar, {{Tab, '_'}, '_'}) of
 	RawGvar ->
 	    case [{Item, Val} || {{_Tab, Item}, Val} <- RawGvar] of
 		[] ->
@@ -2598,6 +3177,8 @@ get_table_properties(Tab) ->
 		    Master = {master_nodes, mnesia:table_info(Tab, master_nodes)},
 		    lists:sort([Size, Memory, Master | Gvar])
 	    end
+    catch error:_ ->
+	    mnesia:abort({no_exists, Tab, all})
     end.
 
 %%%%%%%%%%% RESTORE %%%%%%%%%%%
@@ -2620,15 +3201,15 @@ restore(_Opaque, BadArg) ->
     {aborted, {badarg, BadArg}}.
 restore(Opaque, Args, Module) when is_list(Args), is_atom(Module) ->
     InitR = #r{opaque = Opaque, module = Module},
-    case catch lists:foldl(fun check_restore_arg/2, InitR, Args) of
+    try lists:foldl(fun check_restore_arg/2, InitR, Args) of
 	R when is_record(R, r) ->
 	    case mnesia_bup:read_schema(R#r.module, Opaque) of
 		{error, Reason} ->
 		    {aborted, Reason};
 		BupSchema ->
 		    schema_transaction(fun() -> do_restore(R, BupSchema) end)
-	    end;
-	{'EXIT', Reason} ->
+	    end
+    catch exit:Reason ->
 	    {aborted, Reason}
     end;
 restore(_Opaque, Args, Module) ->
@@ -2681,12 +3262,12 @@ do_restore(R, BupSchema) ->
 
 arrange_restore(R, Fun, Recs) ->
     R2 = R#r{insert_op = Fun, recs = Recs},
-    case mnesia_bup:iterate(R#r.module, fun restore_items/4, R#r.opaque, R2) of
+    case mnesia_bup:iterate(R#r.module, fun restore_items/5, R#r.opaque, R2) of
 	{ok, R3} -> R3#r.recs;
 	{error, Reason} -> mnesia:abort(Reason)
     end.
 
-restore_items([Rec | Recs], Header, Schema, R) ->
+restore_items([Rec | Recs], Header, Schema, Ext, R) ->
     Tab = element(1, Rec),
     case lists:keysearch(Tab, 1, R#r.tables) of
 	{value, {Tab, Where0, Snmp, RecName}} ->
@@ -2699,13 +3280,13 @@ restore_items([Rec | Recs], Header, Schema, R) ->
 	    {Rest, NRecs} = restore_tab_items([Rec | Recs], Tab,
 					      RecName, Where, Snmp,
 					      R#r.recs, R#r.insert_op),
-	    restore_items(Rest, Header, Schema, R#r{recs = NRecs});
+	    restore_items(Rest, Header, Schema, Ext, R#r{recs = NRecs});
 	false ->
 	    Rest = skip_tab_items(Recs, Tab),
-	    restore_items(Rest, Header, Schema, R)
+	    restore_items(Rest, Header, Schema, Ext, R)
     end;
 
-restore_items([], _Header, _Schema, R) ->
+restore_items([], _Header, _Schema, _Ext, R) ->
     R.
 
 restore_func(Tab, R) ->
@@ -2719,8 +3300,14 @@ restore_func(Tab, R) ->
 where_to_commit(Tab, CsList) ->
     Ram =   [{N, ram_copies} || N <- pick(Tab, ram_copies, CsList, [])],
     Disc =  [{N, disc_copies} || N <- pick(Tab, disc_copies, CsList, [])],
-    DiscO = [{N, disc_only_copies} || N <- pick(Tab, disc_only_copies, CsList, [])],
-    Ram ++ Disc ++ DiscO.
+    DiscO = [{N, disc_only_copies} ||
+		N <- pick(Tab, disc_only_copies, CsList, [])],
+    ExtNodes = [{Alias, Mod, pick(Tab, Alias, CsList, [])} ||
+		   {Alias, Mod} <- get_ext_types()],
+    Ext = lists:foldl(fun({Alias, Mod, Ns}, Acc) ->
+			      [{N, {ext, Alias, Mod}} || N <- Ns] ++ Acc
+		      end, [], ExtNodes),
+    Ram ++ Disc ++ DiscO ++ Ext.
 
 %% Changes of the Meta info of schema itself is not allowed
 restore_schema([{schema, schema, _List} | Schema], R) ->
@@ -2799,7 +3386,13 @@ make_dump_tables([schema | _Tabs]) ->
 make_dump_tables([Tab | Tabs]) ->
     get_tid_ts_and_lock(Tab, read),
     TabDef = get_create_list(Tab),
-    DiscResident =  val({Tab, disc_copies}) ++ val({Tab, disc_only_copies}),
+    DiscResident =
+        val({Tab, disc_copies}) ++
+        val({Tab, disc_only_copies}) ++
+        lists:concat([Ns || {{A,M},Ns} <- val({Tab, external_copies}),
+			    lists:member(
+			      mnesia_lib:semantics({ext,A,M},storage),
+			      [disc_copies, disc_only_copies])]),
     verify([], DiscResident,
 	   {"Only allowed on ram_copies", Tab, DiscResident}),
     [{op, dump_table, unknown, TabDef} | make_dump_tables(Tabs)];
@@ -2811,7 +3404,9 @@ merge_schema() ->
     schema_transaction(fun() -> do_merge_schema([]) end).
 
 merge_schema(UserFun) ->
-    schema_transaction(fun() -> UserFun(fun(Arg) -> do_merge_schema(Arg) end) end).
+    schema_transaction(fun() ->
+                               UserFun(fun(Arg) -> do_merge_schema(Arg) end)
+                       end).
 
 do_merge_schema(LockTabs0) ->
     {_Mod, Tid, Ts} = get_tid_ts_and_lock(schema, write),
@@ -2885,39 +3480,22 @@ do_merge_schema(LockTabs0) ->
     end.
 
 fetch_cstructs(Node) ->
-    case need_old_cstructs([Node]) of
-	false ->
-	    rpc:call(Node, mnesia_controller, get_remote_cstructs, []);
-	_Ver ->
-	    case rpc:call(Node, mnesia_controller, get_cstructs, []) of
-		{cstructs, Cs0, RR} ->
-		    {cstructs, [list2cs(cs2list(Cs)) || Cs <- Cs0], RR};
-		Err -> Err
-	    end
+    Convert = mnesia_monitor:needs_protocol_conversion(Node),
+    case rpc:call(Node, mnesia_controller, get_remote_cstructs, [])  of
+	{cstructs, Cs0, RemoteRunning1} when Convert ->
+	    {cstructs, [list2cs(cs2list(Cs)) || Cs <- Cs0], RemoteRunning1};
+	Result ->
+	    Result
     end.
 
 need_old_cstructs() ->
     need_old_cstructs(val({schema, where_to_write})).
 
 need_old_cstructs(Nodes) ->
-    Filter = fun(Node) -> not mnesia_monitor:needs_protocol_conversion(Node) end,
-    case lists:dropwhile(Filter, Nodes) of
+    Filter = fun(Node) -> mnesia_monitor:needs_protocol_conversion(Node) end,
+    case lists:filter(Filter, Nodes) of
 	[] -> false;
-	[Node|_] ->
-	    case rpc:call(Node, mnesia_lib, val, [{schema,cstruct}]) of
-		#cstruct{} ->
-		    %% mnesia_lib:warning("Mnesia on ~p do not need to convert cstruct (~p)~n",
-		    %% 		       [node(), Node]),
-		    false;
-		{badrpc, _} ->
-		    need_old_cstructs(lists:delete(Node,Nodes));
-		Cs when element(1, Cs) == cstruct, tuple_size(Cs) == 17 ->
-		    ver4_4_18;			% Without majority
-		Cs when element(1, Cs) == cstruct, tuple_size(Cs) == 18 ->
-		    ver4_4_19;			% With majority
-		Cs when element(1, Cs) == cstruct, tuple_size(Cs) == 19 ->
-		    ver4_6			% With storage_properties
-	    end
+	Ns -> lists:min([element(1, ?catch_val({protocol, Node})) || Node <- Ns])
     end.
 
 tab_to_nodes(Tab) when is_atom(Tab) ->
@@ -3071,28 +3649,26 @@ do_make_merge_schema(Node, NeedsConv, RemoteCs = #cstruct{}) ->
 %% invariants must be enforced in order to allow merge of cstructs.
 %%
 %% Returns a new cstruct or issues a fatal error
-merge_cstructs(Cs, RemoteCs, Force) ->
-    verify_cstruct(Cs),
-    case catch do_merge_cstructs(Cs, RemoteCs, Force) of
-	{'EXIT', {aborted, _Reason}} when Force == true ->
-	    Cs;
-	{'EXIT', Reason} ->
-	    exit(Reason);
+merge_cstructs(Cs0, RemoteCs, Force) ->
+    Cs = verify_cstruct(Cs0),
+    try do_merge_cstructs(Cs, RemoteCs, Force) of
 	MergedCs when is_record(MergedCs, cstruct) ->
-	    MergedCs;
-	Other ->
-	    throw(Other)
+	    MergedCs
+    catch exit:{aborted, _Reason} when Force == true ->
+	    Cs;
+	  exit:Reason -> exit(Reason);
+	  error:Reason -> exit(Reason)
     end.
 
-do_merge_cstructs(Cs, RemoteCs, Force) ->
-    verify_cstruct(RemoteCs),
+do_merge_cstructs(Cs, RemoteCs0, Force) ->
+    RemoteCs = verify_cstruct(RemoteCs0),
     Ns = mnesia_lib:uniq(mnesia_lib:cs_to_nodes(Cs) ++
 			 mnesia_lib:cs_to_nodes(RemoteCs)),
     {AnythingNew, MergedCs} =
 	merge_storage_type(Ns, false, Cs, RemoteCs, Force),
-    MergedCs2 = merge_versions(AnythingNew, MergedCs, RemoteCs, Force),
-    verify_cstruct(MergedCs2),
-    MergedCs2.
+    verify_cstruct(
+      merge_versions(AnythingNew, MergedCs, RemoteCs, Force)).
+
 
 merge_storage_type([N | Ns], AnythingNew, Cs, RemoteCs, Force) ->
     Local = mnesia_lib:cs_to_storage_type(N, Cs),
@@ -3236,4 +3812,3 @@ unannounce_im_running([N | Ns]) ->
     unannounce_im_running(Ns);
 unannounce_im_running([]) ->
     ok.
-
diff --git a/lib/mnesia/src/mnesia_snmp_hook.erl b/lib/mnesia/src/mnesia_snmp_hook.erl
index 893b39f3c0..58a20c6051 100644
--- a/lib/mnesia/src/mnesia_snmp_hook.erl
+++ b/lib/mnesia/src/mnesia_snmp_hook.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -30,11 +31,6 @@
 
 -include("mnesia.hrl").
 
-val(Var) ->
-    case ?catch_val(Var) of
-	{'EXIT', _ReASoN_} -> mnesia_lib:other_val(Var, _ReASoN_); 
-	_VaLuE_ -> _VaLuE_ 
-    end.
 
 check_ustruct([]) ->
     true;  %% default value, not SNMP'ified
@@ -81,12 +77,12 @@ delete_table(_MnesiaTab, Tree) ->
 %%-----------------------------------------------------------------
    
 update({clear_table, MnesiaTab}) ->
-    Tree = val({MnesiaTab, {index, snmp}}),
+    Tree = mnesia_lib:val({MnesiaTab, {index, snmp}}),
     b_clear(Tree),
     ok;
     
 update({Op, MnesiaTab, MnesiaKey, SnmpKey}) ->
-    Tree = val({MnesiaTab, {index, snmp}}),
+    Tree = mnesia_lib:val({MnesiaTab, {index, snmp}}),
     update(Op, Tree, MnesiaKey, SnmpKey).
 
 update(Op, Tree, MnesiaKey, SnmpKey) ->
@@ -116,7 +112,7 @@ update(Op, Tree, MnesiaKey, SnmpKey) ->
 %%-----------------------------------------------------------------
 
 key_to_oid(Tab,Key) ->
-    Types = val({Tab,snmp}),
+    Types = mnesia_lib:val({Tab,snmp}),
     key_to_oid(Tab, Key, Types).
 	     
 key_to_oid(Tab, Key, [{key, Types}]) ->
@@ -140,7 +136,7 @@ keys_to_oid(N, Key, Oid, Types) ->
 %% This can be lookup up in tree but that might be on a remote node.
 %% It's probably faster to look it up, but use when it migth be remote 
 oid_to_key(Oid, Tab) ->
-    [{key, Types}] = val({Tab,snmp}),
+    [{key, Types}] = mnesia_lib:val({Tab,snmp}),
     oid_to_key_1(Types, Oid). 
 
 oid_to_key_1(integer, [Key])  -> Key;
diff --git a/lib/mnesia/src/mnesia_snmp_sup.erl b/lib/mnesia/src/mnesia_snmp_sup.erl
index 7e86281428..ed579d01c5 100644
--- a/lib/mnesia/src/mnesia_snmp_sup.erl
+++ b/lib/mnesia/src/mnesia_snmp_sup.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_sp.erl b/lib/mnesia/src/mnesia_sp.erl
index 58a177513f..d65c659690 100644
--- a/lib/mnesia/src/mnesia_sp.erl
+++ b/lib/mnesia/src/mnesia_sp.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
diff --git a/lib/mnesia/src/mnesia_subscr.erl b/lib/mnesia/src/mnesia_subscr.erl
index 8f78dc55e8..c2748f5bae 100644
--- a/lib/mnesia/src/mnesia_subscr.erl
+++ b/lib/mnesia/src/mnesia_subscr.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -186,11 +187,11 @@ patch_record(Tab, Obj) ->
     end.
 
 what(Tab, Tid, {RecName, Key}, delete, undefined) ->
-    case catch mnesia_lib:db_get(Tab, Key) of
-	Old when is_list(Old) -> %% Op only allowed for set table.
-	    {mnesia_table_event, {delete, Tab, {RecName, Key}, Old, Tid}};
-	_ ->
-	    %% Record just deleted by a dirty_op or 
+    try mnesia_lib:db_get(Tab, Key) of
+	Old -> %% Op only allowed for set table.
+	    {mnesia_table_event, {delete, Tab, {RecName, Key}, Old, Tid}}
+    catch error:_ ->
+	    %% Record just deleted by a dirty_op or
 	    %% the whole table has been deleted
 	    ignore
     end;
@@ -199,12 +200,14 @@ what(Tab, Tid, Obj, delete, Old) ->
 what(Tab, Tid, Obj, delete_object, _Old) ->
     {mnesia_table_event, {delete, Tab, Obj, [Obj], Tid}};
 what(Tab, Tid, Obj, write, undefined) ->
-    case catch mnesia_lib:db_get(Tab, element(2, Obj)) of
-	Old when is_list(Old) ->
-	    {mnesia_table_event, {write, Tab, Obj, Old, Tid}};
-	{'EXIT', _} ->
+    try	mnesia_lib:db_get(Tab, element(2, Obj)) of
+	Old ->
+	    {mnesia_table_event, {write, Tab, Obj, Old, Tid}}
+    catch error:_ ->
 	    ignore
-    end.
+    end;
+what(Tab, Tid, Obj, write, Old) ->
+    {mnesia_table_event, {write, Tab, Obj, Old, Tid}}.
 
 deliver(_, ignore) -> 
     ok;
@@ -223,7 +226,7 @@ call(Msg) ->
 	    Res = gen_server:call(Pid, Msg, infinity),
             %% We get an exit signal if server dies
             receive
-                {'EXIT', _Pid, _Reason} ->
+                {'EXIT', Pid, _Reason} ->
                     {error, {node_not_running, node()}}
             after 0 ->
                     Res
@@ -384,12 +387,12 @@ activate(ClientPid, What, Var, OldSubscribers, SubscrTab) ->
     case lists:member(ClientPid, Old) of
 	false ->
 	    %% Don't care about checking old links
-	    case catch link(ClientPid) of
+	    try link(ClientPid) of
 		true ->
 		    ?ets_insert(SubscrTab, {ClientPid, What}),
 		    add_subscr(Var, What, ClientPid),
-		    {ok, node()};
-		{'EXIT', _Reason} ->
+		    {ok, node()}
+	    catch error:_ ->
 		    {error, {no_exists, ClientPid}}
 	    end;
 	true ->
@@ -441,11 +444,10 @@ add_subscr({Tab, commit_work}, What, Pid) ->
 
 deactivate(ClientPid, What, Var, SubscrTab) ->
     ?ets_match_delete(SubscrTab, {ClientPid, What}),
-    case catch ?ets_lookup_element(SubscrTab, ClientPid, 1) of
-	List when is_list(List) ->
-	    ignore;
-	{'EXIT', _} ->
-	    unlink(ClientPid)
+    try
+	?ets_lookup_element(SubscrTab, ClientPid, 1),
+	ignore
+    catch error:_ -> unlink(ClientPid)
     end,
     try
 	del_subscr(Var, What, ClientPid),
diff --git a/lib/mnesia/src/mnesia_sup.erl b/lib/mnesia/src/mnesia_sup.erl
index 8443fefe7f..4aece81308 100644
--- a/lib/mnesia/src/mnesia_sup.erl
+++ b/lib/mnesia/src/mnesia_sup.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -59,9 +60,10 @@ init() ->
     Flags = {one_for_all, 0, 3600}, % Should be rest_for_one policy
 
     Event = event_procs(),
+    Ext = ext_procs(),
     Kernel = kernel_procs(),
 
-    {ok, {Flags, Event ++ Kernel}}.
+    {ok, {Flags, Event ++ Ext ++ Kernel}}.
 
 event_procs() ->
     KillAfter = timer:seconds(30),
@@ -74,6 +76,11 @@ kernel_procs() ->
     KA = infinity,
     [{K, {K, start, []}, permanent, KA, supervisor, [K, supervisor]}].
 
+ext_procs() ->
+    K = mnesia_ext_sup,
+    KA = infinity,
+    [{K, {K, start, []}, permanent, KA, supervisor, [K, supervisor]}].
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% event handler
 
diff --git a/lib/mnesia/src/mnesia_text.erl b/lib/mnesia/src/mnesia_text.erl
index 0906d18da9..21adca813a 100644
--- a/lib/mnesia/src/mnesia_text.erl
+++ b/lib/mnesia/src/mnesia_text.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %% 
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
-%% 
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %% 
 %% %CopyrightEnd%
 %%
@@ -84,8 +85,12 @@ validate_tab({Tabname, RecName, List}) ->
 validate_tab(_) -> error(badtab).
 
 make_tabs([{Tab, Def} | Tail]) ->
-    case catch mnesia:table_info(Tab, where_to_read) of
-	{'EXIT', _} -> %% non-existing table
+    try mnesia:table_info(Tab, where_to_read) of
+	Node ->
+	    io:format("** Table ~w already exists on ~p, just entering data~n",
+		      [Tab, Node]),
+	    make_tabs(Tail)
+    catch exit:_ -> %% non-existing table
 	    case mnesia:create_table(Tab, Def) of
 		{aborted, Reason} ->
 		    io:format("** Failed to create table ~w ~n"
@@ -95,11 +100,7 @@ make_tabs([{Tab, Def} | Tail]) ->
 		_ -> 
 		    io:format("New table ~w~n", [Tab]),
 		    make_tabs(Tail)
-	    end;
-	Node ->
-	    io:format("** Table ~w already exists on ~p, just entering data~n",
-		      [Tab, Node]),
-	    make_tabs(Tail)
+	    end
     end;
 
 make_tabs([]) -> 
@@ -118,11 +119,9 @@ load_data(L) ->
 parse(File) ->
     case file(File) of
 	{ok, Terms} ->
-	    case catch collect(Terms) of
-		{error, X} ->
-		    {error, X};
-		Other ->
-		    {ok, Other}
+	    try collect(Terms) of
+		Other -> {ok, Other}
+	    catch throw:Error -> Error
 	    end;
 	Other ->
 	    Other
diff --git a/lib/mnesia/src/mnesia_tm.erl b/lib/mnesia/src/mnesia_tm.erl
index e54e5c4e88..b116b48312 100644
--- a/lib/mnesia/src/mnesia_tm.erl
+++ b/lib/mnesia/src/mnesia_tm.erl
@@ -1,18 +1,19 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
 %%
-%% The contents of this file are subject to the Erlang Public License,
-%% Version 1.1, (the "License"); you may not use this file except in
-%% compliance with the License. You should have received a copy of the
-%% Erlang Public License along with this software. If not, it can be
-%% retrieved online at http://www.erlang.org/.
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
 %%
-%% Software distributed under the License is distributed on an "AS IS"
-%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
-%% the License for the specific language governing rights and limitations
-%% under the License.
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
 %%
 %% %CopyrightEnd%
 %%
@@ -41,7 +42,8 @@
 	 put_activity_id/2,
 	 block_tab/1,
 	 unblock_tab/1,
-	 fixtable/3
+	 fixtable/3,
+	 new_cr_format/1
 	]).
 
 %% sys callback functions
@@ -51,6 +53,7 @@
 	]).
 
 -include("mnesia.hrl").
+
 -import(mnesia_lib, [set/2]).
 -import(mnesia_lib, [fatal/2, verbose/2, dbg_out/2]).
 
@@ -119,7 +122,7 @@ init(Parent) ->
 
 val(Var) ->
     case ?catch_val(Var) of
-	{'EXIT', _ReASoN_} -> mnesia_lib:other_val(Var, _ReASoN_);
+	{'EXIT', _} -> mnesia_lib:other_val(Var);
 	_VaLuE_ -> _VaLuE_
     end.
 
@@ -181,9 +184,10 @@ mnesia_down(Node) ->
     %% mnesia_monitor takes care of the sync
     case whereis(?MODULE) of
 	undefined ->
-	    mnesia_monitor:mnesia_down(?MODULE, {Node, []});
+	    mnesia_monitor:mnesia_down(?MODULE, Node);
 	Pid ->
-	    Pid ! {mnesia_down, Node}
+	    Pid ! {mnesia_down, Node},
+	    ok
     end.
 
 prepare_checkpoint(Nodes, Cp) ->
@@ -203,10 +207,10 @@ doit_loop(#state{coordinators=Coordinators,participants=Participants,supervisor=
 	{_From, {async_dirty, Tid, Commit, Tab}} ->
 	    case lists:member(Tab, State#state.blocked_tabs) of
 		false ->
-		    do_async_dirty(Tid, Commit, Tab),
+		    do_async_dirty(Tid, new_cr_format(Commit), Tab),
 		    doit_loop(State);
 		true ->
-		    Item = {async_dirty, Tid, Commit, Tab},
+		    Item = {async_dirty, Tid, new_cr_format(Commit), Tab},
 		    State2 = State#state{dirty_queue = [Item | State#state.dirty_queue]},
 		    doit_loop(State2)
 	    end;
@@ -214,20 +218,16 @@ doit_loop(#state{coordinators=Coordinators,participants=Participants,supervisor=
 	{From, {sync_dirty, Tid, Commit, Tab}} ->
 	    case lists:member(Tab, State#state.blocked_tabs) of
 		false ->
-		    do_sync_dirty(From, Tid, Commit, Tab),
+		    do_sync_dirty(From, Tid, new_cr_format(Commit), Tab),
 		    doit_loop(State);
 		true ->
-		    Item = {sync_dirty, From, Tid, Commit, Tab},
+		    Item = {sync_dirty, From, Tid, new_cr_format(Commit), Tab},
 		    State2 = State#state{dirty_queue = [Item | State#state.dirty_queue]},
 		    doit_loop(State2)
 	    end;
 
 	{From, start_outer} -> %% Create and associate ets_tab with Tid
-	    case catch ?ets_new_table(mnesia_trans_store, [bag, public]) of
-		{'EXIT', Reason} -> %% system limit
-		    Msg = "Cannot create an ets table for the "
-	                  "local transaction store",
-		    reply(From, {error, {system_limit, Msg, Reason}}, State);
+	    try ?ets_new_table(mnesia_trans_store, [bag, public]) of
 		Etab ->
 		    tmlink(From),
 		    C = mnesia_recover:incr_trans_tid_serial(),
@@ -236,12 +236,17 @@ doit_loop(#state{coordinators=Coordinators,participants=Participants,supervisor=
 		    A2 = gb_trees:insert(Tid,[Etab],Coordinators),
 		    S2 = State#state{coordinators = A2},
 		    reply(From, {new_tid, Tid, Etab}, S2)
+	    catch error:Reason -> %% system limit
+		    Msg = "Cannot create an ets table for the "
+			"local transaction store",
+		    reply(From, {error, {system_limit, Msg, Reason}}, State)
 	    end;
 
-	{From, {ask_commit, Protocol, Tid, Commit, DiscNs, RamNs}} ->
+	{From, {ask_commit, Protocol, Tid, Commit0, DiscNs, RamNs}} ->
 	    ?eval_debug_fun({?MODULE, doit_ask_commit},
 			    [{tid, Tid}, {prot, Protocol}]),
 	    mnesia_checkpoint:tm_enter_pending(Tid, DiscNs, RamNs),
+	    Commit = new_cr_format(Commit0),
 	    Pid =
 		case Protocol of
 		    asym_trans when node(Tid#tid.pid) /= node() ->
@@ -338,15 +343,15 @@ doit_loop(#state{coordinators=Coordinators,participants=Participants,supervisor=
 	    end;
 
 	{From, {add_store, Tid}} -> %% new store for nested  transaction
-	    case catch ?ets_new_table(mnesia_trans_store, [bag, public]) of
-		{'EXIT', Reason} -> %% system limit
-		    Msg = "Cannot create an ets table for a nested "
-                          "local transaction store",
-		    reply(From, {error, {system_limit, Msg, Reason}}, State);
+	    try ?ets_new_table(mnesia_trans_store, [bag, public]) of
 		Etab ->
 		    A2 = add_coord_store(Coordinators, Tid, Etab),
 		    reply(From, {new_store, Etab},
 			  State#state{coordinators = A2})
+	    catch error:Reason -> %% system limit
+		    Msg = "Cannot create an ets table for a nested "
+			"local transaction store",
+		    reply(From, {error, {system_limit, Msg, Reason}}, State)
 	    end;
 
 	{From, {del_store, Tid, Current, Obsolete, PropagateStore}} ->
@@ -403,7 +408,9 @@ doit_loop(#state{coordinators=Coordinators,participants=Participants,supervisor=
 	    Tids = gb_trees:keys(Participants),
 	    reconfigure_participants(N, gb_trees:values(Participants)),
 	    NewState = clear_fixtable(N, State),
-	    mnesia_monitor:mnesia_down(?MODULE, {N, Tids}),
+
+	    mnesia_locker:mnesia_down(N, Tids),
+	    mnesia_monitor:mnesia_down(?MODULE, N),
 	    doit_loop(NewState);
 
 	{From, {unblock_me, Tab}} ->
@@ -468,13 +475,13 @@ doit_loop(#state{coordinators=Coordinators,participants=Participants,supervisor=
 
 do_sync_dirty(From, Tid, Commit, _Tab) ->
     ?eval_debug_fun({?MODULE, sync_dirty, pre}, [{tid, Tid}]),
-    Res = (catch do_dirty(Tid, Commit)),
+    Res = do_dirty(Tid, Commit),
     ?eval_debug_fun({?MODULE, sync_dirty, post}, [{tid, Tid}]),
     From ! {?MODULE, node(), {dirty_res, Res}}.
 
 do_async_dirty(Tid, Commit, _Tab) ->
     ?eval_debug_fun({?MODULE, async_dirty, pre}, [{tid, Tid}]),
-    catch do_dirty(Tid, Commit),
+    do_dirty(Tid, Commit),
     ?eval_debug_fun({?MODULE, async_dirty, post}, [{tid, Tid}]).
 
 
@@ -498,7 +505,7 @@ process_dirty_queue(_Tab, []) ->
     [].
 
 prepare_pending_coordinators([{Tid, [Store | _Etabs]} | Coords], IgnoreNew) ->
-    case catch ?ets_lookup(Store, pending) of
+    try ?ets_lookup(Store, pending) of
 	[] ->
 	    prepare_pending_coordinators(Coords, IgnoreNew);
 	[Pending] ->
@@ -508,8 +515,8 @@ prepare_pending_coordinators([{Tid, [Store | _Etabs]} | Coords], IgnoreNew) ->
 		true ->
 		    ignore
 	    end,
-	    prepare_pending_coordinators(Coords, IgnoreNew);
-	{'EXIT', _} ->
+	    prepare_pending_coordinators(Coords, IgnoreNew)
+    catch error:_ ->
 	    prepare_pending_coordinators(Coords, IgnoreNew)
     end;
 prepare_pending_coordinators([], _IgnoreNew) ->
@@ -570,11 +577,7 @@ recover_coordinator(Tid, Etabs) ->
     Store = hd(Etabs),
     CheckNodes = get_elements(nodes,Store),
     TellNodes = CheckNodes -- [node()],
-    case catch arrange(Tid, Store, async) of
-	{'EXIT', Reason} ->
-	    dbg_out("Recovery of coordinator ~p failed:~n", [Tid, Reason]),
-	    Protocol = asym_trans,
-	    tell_outcome(Tid, Protocol, node(), CheckNodes, TellNodes);
+    try arrange(Tid, Store, async) of
 	{_N, Prep} ->
 	    %% Tell the participants about the outcome
 	    Protocol = Prep#prep.protocol,
@@ -593,6 +596,11 @@ recover_coordinator(Tid, Etabs) ->
 		false ->  %% When killed before store havn't been copied to
 		    ok    %% to the new nested trans store.
 	    end
+    catch _:Reason ->
+	    dbg_out("Recovery of coordinator ~p failed:~n",
+		    [Tid, {Reason, erlang:get_stacktrace()}]),
+	    Protocol = asym_trans,
+	    tell_outcome(Tid, Protocol, node(), CheckNodes, TellNodes)
     end,
     erase_ets_tabs(Etabs),
     transaction_terminated(Tid),
@@ -721,33 +729,25 @@ non_transaction(OldState={_,_,Trans}, Fun, Args, ActivityKind, Mod)
 	       _ -> async
 	   end,
     case transaction(OldState, Fun, Args, infinity, Mod, Kind) of
-	{atomic, Res} ->
-	    Res;
-	{aborted,Res} ->
-	    exit(Res)
+	{atomic, Res} -> Res;
+	{aborted,Res} -> exit(Res)
     end;
 non_transaction(OldState, Fun, Args, ActivityKind, Mod) ->
     Id = {ActivityKind, self()},
     NewState = {Mod, Id, non_transaction},
     put(mnesia_activity_state, NewState),
-    %% I Want something uniqe here, references are expensive
-    Ref = mNeSia_nOn_TrAnSacTioN,
-    RefRes = (catch {Ref, apply(Fun, Args)}),
-    case OldState of
-	undefined -> erase(mnesia_activity_state);
-	_ -> put(mnesia_activity_state, OldState)
-    end,
-    case RefRes of
-	{Ref, Res} ->
-	    case Res of
-		{'EXIT', Reason} -> exit(Reason);
-		{aborted, Reason} -> mnesia:abort(Reason);
-		_ -> Res
-	    end;
-	{'EXIT', Reason} ->
-	    exit(Reason);
-	Throw ->
-	    throw(Throw)
+    try apply(Fun, Args) of
+	{'EXIT', Reason} -> exit(Reason);
+	{aborted, Reason} -> mnesia:abort(Reason);
+	Res -> Res
+    catch
+	throw:Throw -> throw(Throw);
+	_:Reason    -> exit(Reason)
+    after
+	case OldState of
+	    undefined -> erase(mnesia_activity_state);
+	    _ -> put(mnesia_activity_state, OldState)
+	end
     end.
 
 transaction(OldTidTs, Fun, Args, Retries, Mod, Type) ->
@@ -807,23 +807,28 @@ insert_objs([], _Tab) ->
     ok.
 
 execute_transaction(Fun, Args, Factor, Retries, Type) ->
-    case catch apply_fun(Fun, Args, Type) of
-	{'EXIT', Reason} ->
-	    check_exit(Fun, Args, Factor, Retries, Reason, Type);
+    try apply_fun(Fun, Args, Type) of
 	{atomic, Value} ->
 	    mnesia_lib:incr_counter(trans_commits),
 	    erase(mnesia_activity_state),
 	    %% no need to clear locks, already done by commit ...
 	    %% Flush any un processed mnesia_down messages we might have
 	    flush_downs(),
-	    catch unlink(whereis(?MODULE)),
+	    ?SAFE(unlink(whereis(?MODULE))),
 	    {atomic, Value};
+	{do_abort, Reason} ->
+	    check_exit(Fun, Args, Factor, Retries, {aborted, Reason}, Type);
 	{nested_atomic, Value} ->
 	    mnesia_lib:incr_counter(trans_commits),
-	    {atomic, Value};
-	Value -> %% User called throw
+	    {atomic, Value}
+    catch throw:Value ->  %% User called throw
 	    Reason = {aborted, {throw, Value}},
-	    return_abort(Fun, Args, Reason)
+	    return_abort(Fun, Args, Reason);
+	  error:Reason ->
+	    ST = erlang:get_stacktrace(),
+	    check_exit(Fun, Args, Factor, Retries, {Reason,ST}, Type);
+	  _:Reason ->
+	    check_exit(Fun, Args, Factor, Retries, Reason, Type)
     end.
 
 apply_fun(Fun, Args, Type) ->
@@ -833,10 +838,10 @@ apply_fun(Fun, Args, Type) ->
             {atomic, Result};
         do_commit_nested ->
             {nested_atomic, Result};
-        {do_abort, {aborted, Reason}} ->
-            {'EXIT', {aborted, Reason}};
-        {do_abort, Reason} ->
-            {'EXIT', {aborted, Reason}}
+	{do_abort, {aborted, Reason}} ->
+	    {do_abort, Reason};
+	{do_abort, _} = Abort ->
+	    Abort
     end.
 
 check_exit(Fun, Args, Factor, Retries, Reason, Type) ->
@@ -940,7 +945,7 @@ return_abort(Fun, Args, Reason)  ->
     OldStore = Ts#tidstore.store,
     Nodes = get_elements(nodes, OldStore),
     intercept_friends(Tid, Ts),
-    catch mnesia_lib:incr_counter(trans_failures),
+    ?SAFE(mnesia_lib:incr_counter(trans_failures)),
     Level = Ts#tidstore.level,
     if
 	Level == 1 ->
@@ -948,7 +953,7 @@ return_abort(Fun, Args, Reason)  ->
 	    ?MODULE ! {delete_transaction, Tid},
 	    erase(mnesia_activity_state),
 	    flush_downs(),
-	    catch unlink(whereis(?MODULE)),
+	    ?SAFE(unlink(whereis(?MODULE))),
 	    {aborted, mnesia_lib:fix_error(Reason)};
 	true ->
 	    %% Nested transaction
@@ -1002,11 +1007,11 @@ erase_activity_id() ->
     erase(mnesia_activity_state).
 
 get_elements(Type,Store) ->
-    case catch ?ets_lookup(Store, Type) of
+    try ?ets_lookup(Store, Type) of
 	[] -> [];
 	[{_,Val}] -> [Val];
-	{'EXIT', _} -> [];
 	Vals -> [Val|| {_,Val} <- Vals]
+    catch error:_ -> []
     end.
 
 opt_propagate_store(_Current, _Obsolete, false) ->
@@ -1029,7 +1034,7 @@ intercept_friends(_Tid, Ts) ->
 
 intercept_best_friend([],_) ->    ok;
 intercept_best_friend([{stop,Fun} | R],Ignore) ->
-    catch Fun(),
+    ?CATCH(Fun()),
     intercept_best_friend(R,Ignore);
 intercept_best_friend([Pid | R],false) ->
     Pid ! {activity_ended, undefined, self()},
@@ -1043,25 +1048,12 @@ wait_for_best_friend(Pid, Timeout) ->
 	{'EXIT', Pid, _} -> ok;
 	{activity_ended, _, Pid} -> ok
     after Timeout ->
-	    case my_process_is_alive(Pid) of
+	    case erlang:is_process_alive(Pid) of
 		true -> wait_for_best_friend(Pid, 1000);
 		false -> ok
 	    end
     end.
 
-my_process_is_alive(Pid) ->
-    case catch erlang:is_process_alive(Pid) of % New BIF in R5
-	true ->
-	    true;
-	false ->
-	    false;
-	{'EXIT', _} -> % Pre R5 backward compatibility
-	    case process_info(Pid, message_queue_len) of
-		undefined -> false;
-		_ -> true
-	    end
-    end.
-
 dirty(Protocol, Item) ->
     {{Tab, Key}, _Val, _Op} = Item,
     Tid = {dirty, self()},
@@ -1141,30 +1133,20 @@ arrange(Tid, Store, Type) ->
 	    async -> #prep{protocol = sym_trans, records = Recs};
 	    sync -> #prep{protocol = sync_sym_trans, records = Recs}
 	end,
-    case catch do_arrange(Tid, Store, Key, Prep, N) of
-	{'EXIT', Reason} ->
-	    dbg_out("do_arrange failed ~p ~p~n", [Reason, Tid]),
-	    case Reason of
-		{aborted, R} ->
-		    mnesia:abort(R);
-		_ ->
-		    mnesia:abort(Reason)
-	    end;
-	{New, Prepared} ->
-	    {New, Prepared#prep{records = reverse(Prepared#prep.records)}}
-    end.
+    {New, Prepared} = do_arrange(Tid, Store, Key, Prep, N),
+    {New, Prepared#prep{records = reverse(Prepared#prep.records)}}.
 
 reverse([]) ->
     [];
 reverse([H=#commit{ram_copies=Ram, disc_copies=DC,
-		   disc_only_copies=DOC,snmp = Snmp}
+		   disc_only_copies=DOC, ext=Ext}
 	 |R]) ->
     [
      H#commit{
-       ram_copies       =  lists:reverse(Ram),
-       disc_copies      =  lists:reverse(DC),
-       disc_only_copies =  lists:reverse(DOC),
-       snmp             = lists:reverse(Snmp)
+       ram_copies       = lists:reverse(Ram),
+       disc_copies      = lists:reverse(DC),
+       disc_only_copies = lists:reverse(DOC),
+       ext              = [{Type, lists:reverse(E)} || {Type,E} <- Ext]
       }
      | reverse(R)].
 
@@ -1331,8 +1313,13 @@ pick_node({dirty,_}, Node, [], Done) ->
 pick_node(_Tid, Node, [], _Done) ->
     mnesia:abort({bad_commit, {missing_lock, Node}}).
 
-prepare_node(Node, Storage, [Item | Items], Rec, Kind) when Kind == snmp ->
-    Rec2 = Rec#commit{snmp = [Item | Rec#commit.snmp]},
+prepare_node(Node, Storage, [Item | Items], #commit{ext=Ext0}=Rec, Kind) when Kind == snmp ->
+    Rec2 = case lists:keytake(snmp, 1, Ext0) of
+	       false ->
+		   Rec#commit{ext = [{snmp,[Item]}|Ext0]};
+	       {_, {snmp,Snmp},Ext} ->
+		   Rec#commit{ext = [{snmp,[Item|Snmp]}|Ext]}
+	   end,
     prepare_node(Node, Storage, Items, Rec2, Kind);
 prepare_node(Node, Storage, [Item | Items], Rec, Kind) when Kind /= schema ->
     Rec2 =
@@ -1343,7 +1330,15 @@ prepare_node(Node, Storage, [Item | Items], Rec, Kind) when Kind /= schema ->
 		Rec#commit{disc_copies = [Item | Rec#commit.disc_copies]};
 	    disc_only_copies ->
 		Rec#commit{disc_only_copies =
-			   [Item | Rec#commit.disc_only_copies]}
+			   [Item | Rec#commit.disc_only_copies]};
+	    {ext, Alias, Mod} ->
+		Ext0 = Rec#commit.ext,
+		case lists:keytake(ext_copies, 1, Ext0) of
+		    false ->
+			Rec#commit{ext = [{ext_copies, [{{ext,Alias,Mod}, Item}]}|Ext0]};
+		    {_,{_,EC},Ext} ->
+			Rec#commit{ext = [{ext_copies, [{{ext,Alias,Mod}, Item}|EC]}|Ext]}
+		end
 	end,
     prepare_node(Node, Storage, Items, Rec2, Kind);
 prepare_node(_Node, _Storage, Items, Rec, Kind)
@@ -1519,7 +1514,7 @@ multi_commit(asym_trans, Majority, Tid, CR, Store) ->
     Pending = mnesia_checkpoint:tm_enter_pending(Tid, DiscNs, RamNs),
     ?ets_insert(Store, Pending),
     {WaitFor, Local} = ask_commit(asym_trans, Tid, CR2, DiscNs, RamNs),
-    SchemaPrep = (catch mnesia_schema:prepare_commit(Tid, Local, {coord, WaitFor})),
+    SchemaPrep = ?CATCH(mnesia_schema:prepare_commit(Tid, Local, {coord, WaitFor})),
     {Votes, Pids} = rec_all(WaitFor, Tid, do_commit, []),
 
     ?eval_debug_fun({?MODULE, multi_commit_asym_got_votes},
@@ -1586,7 +1581,7 @@ rec_acc_pre_commit([Pid | Tail], Tid, Store, Commit, Res, DumperMode,
 			       GoodPids, SchemaAckPids);
 	{mnesia_down, Node} when Node == node(Pid) ->
 	    AbortRes = {do_abort, {bad_commit, Node}},
-	    catch Pid ! {Tid, AbortRes},  %% Tell him that he has died
+	    ?SAFE(Pid ! {Tid, AbortRes}),  %% Tell him that he has died
 	    rec_acc_pre_commit(Tail, Tid, Store, Commit, AbortRes, DumperMode,
 			       GoodPids, SchemaAckPids)
     end;
@@ -1663,7 +1658,7 @@ commit_participant(Coord, Tid, C = #commit{}, DiscNs, RamNs) ->
 
 commit_participant(Coord, Tid, Bin, C0, DiscNs, _RamNs) ->
     ?eval_debug_fun({?MODULE, commit_participant, pre}, [{tid, Tid}]),
-    case catch mnesia_schema:prepare_commit(Tid, C0, {part, Coord}) of
+    try mnesia_schema:prepare_commit(Tid, C0, {part, Coord}) of
 	{Modified, C = #commit{}, DumperMode} ->
 	    %% If we can not find any local unclear decision
 	    %% we should presume abort at startup recovery
@@ -1712,13 +1707,10 @@ commit_participant(Coord, Tid, Bin, C0, DiscNs, _RamNs) ->
 			    ?eval_debug_fun({?MODULE, commit_participant, undo_prepare},
 					    [{tid, Tid}]);
 
-			{'EXIT', _, _} ->
+			{'EXIT', _MnesiaTM, Reason} ->
+			    reply(Coord, {do_abort, Tid, self(), {bad_commit,Reason}}),
 			    mnesia_recover:log_decision(D#decision{outcome = aborted}),
-			    ?eval_debug_fun({?MODULE, commit_participant, exit_log_abort},
-					    [{tid, Tid}]),
-			    mnesia_schema:undo_prepare_commit(Tid, C0),
-			    ?eval_debug_fun({?MODULE, commit_participant, exit_undo_prepare},
-					    [{tid, Tid}]);
+			    mnesia_schema:undo_prepare_commit(Tid, C0);
 
 			Msg ->
 			    verbose("** ERROR ** commit_participant ~p, got unexpected msg: ~p~n",
@@ -1739,9 +1731,8 @@ commit_participant(Coord, Tid, Bin, C0, DiscNs, _RamNs) ->
 		    reply(Coord, {do_abort, Tid, self(), {bad_commit,internal}}),
 		    verbose("** ERROR ** commit_participant ~p, got unexpected msg: ~p~n",
 			    [Tid, Msg])
-	    end;
-
-	{'EXIT', Reason} ->
+	    end
+    catch _:Reason ->
 	    ?eval_debug_fun({?MODULE, commit_participant, vote_no},
 			    [{tid, Tid}]),
 	    reply(Coord, {vote_no, Tid, Reason}),
@@ -1774,180 +1765,192 @@ do_commit(Tid, Bin) when is_binary(Bin) ->
     do_commit(Tid, binary_to_term(Bin));
 do_commit(Tid, C) ->
     do_commit(Tid, C, optional).
+
 do_commit(Tid, Bin, DumperMode) when is_binary(Bin) ->
     do_commit(Tid, binary_to_term(Bin), DumperMode);
 do_commit(Tid, C, DumperMode) ->
     mnesia_dumper:update(Tid, C#commit.schema_ops, DumperMode),
-    R  = do_snmp(Tid, C#commit.snmp),
+    R  = do_snmp(Tid, proplists:get_value(snmp, C#commit.ext, [])),
     R2 = do_update(Tid, ram_copies, C#commit.ram_copies, R),
     R3 = do_update(Tid, disc_copies, C#commit.disc_copies, R2),
     R4 = do_update(Tid, disc_only_copies, C#commit.disc_only_copies, R3),
+    R5 = do_update_ext(Tid, C#commit.ext, R4),
     mnesia_subscr:report_activity(Tid),
-    R4.
+    R5.
+
+%% This could/should be optimized
+do_update_ext(_Tid, [], OldRes) -> OldRes;
+do_update_ext(Tid, Ext, OldRes) ->
+    case lists:keyfind(ext_copies, 1, Ext) of
+	false -> OldRes;
+	{_, Ops} ->
+	    Do = fun({{ext, _,_} = Storage, Op}, R) ->
+			 do_update(Tid, Storage, [Op], R)
+		 end,
+	    lists:foldl(Do, OldRes, Ops)
+    end.
 
 %% Update the items
 do_update(Tid, Storage, [Op | Ops], OldRes) ->
-    case catch do_update_op(Tid, Storage, Op) of
-	ok ->
-	    do_update(Tid, Storage, Ops, OldRes);
-	{'EXIT', Reason} ->
+    try do_update_op(Tid, Storage, Op) of
+	ok ->     do_update(Tid, Storage, Ops, OldRes);
+	NewRes -> do_update(Tid, Storage, Ops, NewRes)
+    catch _:Reason ->
 	    %% This may only happen when we recently have
 	    %% deleted our local replica, changed storage_type
 	    %% or transformed table
 	    %% BUGBUG: Updates may be lost if storage_type is changed.
 	    %%         Determine actual storage type and try again.
 	    %% BUGBUG: Updates may be lost if table is transformed.
-
+	    ST = erlang:get_stacktrace(),
 	    verbose("do_update in ~w failed: ~p -> {'EXIT', ~p}~n",
-		    [Tid, Op, Reason]),
-	    do_update(Tid, Storage, Ops, OldRes);
-	NewRes ->
-	    do_update(Tid, Storage, Ops, NewRes)
+		    [Tid, Op, {Reason, ST}]),
+	    do_update(Tid, Storage, Ops, OldRes)
     end;
 do_update(_Tid, _Storage, [], Res) ->
     Res.
 
 do_update_op(Tid, Storage, {{Tab, K}, Obj, write}) ->
-    commit_write(?catch_val({Tab, commit_work}), Tid,
+    commit_write(?catch_val({Tab, commit_work}), Tid, Storage,
 		 Tab, K, Obj, undefined),
     mnesia_lib:db_put(Storage, Tab, Obj);
 
 do_update_op(Tid, Storage, {{Tab, K}, Val, delete}) ->
-    commit_delete(?catch_val({Tab, commit_work}), Tid, Tab, K, Val, undefined),
+    commit_delete(?catch_val({Tab, commit_work}), Tid, Storage, Tab, K, Val, undefined),
     mnesia_lib:db_erase(Storage, Tab, K);
 
 do_update_op(Tid, Storage, {{Tab, K}, {RecName, Incr}, update_counter}) ->
     {NewObj, OldObjs} =
-        case catch mnesia_lib:db_update_counter(Storage, Tab, K, Incr) of
-            NewVal when is_integer(NewVal), NewVal >= 0 ->
-                {{RecName, K, NewVal}, [{RecName, K, NewVal - Incr}]};
-            _ when Incr > 0 ->
+        try
+	    NewVal = mnesia_lib:db_update_counter(Storage, Tab, K, Incr),
+	    true = is_integer(NewVal) andalso (NewVal >= 0),
+	    {{RecName, K, NewVal}, [{RecName, K, NewVal - Incr}]}
+	catch error:_ when Incr > 0 ->
                 New = {RecName, K, Incr},
                 mnesia_lib:db_put(Storage, Tab, New),
                 {New, []};
-	    _ ->
+	      error:_ ->
 		Zero = {RecName, K, 0},
 		mnesia_lib:db_put(Storage, Tab, Zero),
 		{Zero, []}
         end,
-    commit_update(?catch_val({Tab, commit_work}), Tid, Tab,
+    commit_update(?catch_val({Tab, commit_work}), Tid, Storage, Tab,
 		  K, NewObj, OldObjs),
     element(3, NewObj);
 
 do_update_op(Tid, Storage, {{Tab, Key}, Obj, delete_object}) ->
     commit_del_object(?catch_val({Tab, commit_work}),
-		      Tid, Tab, Key, Obj, undefined),
+		      Tid, Storage, Tab, Key, Obj),
     mnesia_lib:db_match_erase(Storage, Tab, Obj);
 
 do_update_op(Tid, Storage, {{Tab, Key}, Obj, clear_table}) ->
-    commit_clear(?catch_val({Tab, commit_work}), Tid, Tab, Key, Obj),
+    commit_clear(?catch_val({Tab, commit_work}), Tid, Storage, Tab, Key, Obj),
     mnesia_lib:db_match_erase(Storage, Tab, Obj).
 
-commit_write([], _, _, _, _, _) -> ok;
-commit_write([{checkpoints, CpList}|R], Tid, Tab, K, Obj, Old) ->
+commit_write([], _, _, _, _, _, _) -> ok;
+commit_write([{checkpoints, CpList}|R], Tid, Storage, Tab, K, Obj, Old) ->
     mnesia_checkpoint:tm_retain(Tid, Tab, K, write, CpList),
-    commit_write(R, Tid, Tab, K, Obj, Old);
-commit_write([H|R], Tid, Tab, K, Obj, Old)
+    commit_write(R, Tid, Storage, Tab, K, Obj, Old);
+commit_write([H|R], Tid, Storage, Tab, K, Obj, Old)
   when element(1, H) == subscribers ->
     mnesia_subscr:report_table_event(H, Tab, Tid, Obj, write, Old),
-    commit_write(R, Tid, Tab, K, Obj, Old);
-commit_write([H|R], Tid, Tab, K, Obj, Old)
+    commit_write(R, Tid, Storage, Tab, K, Obj, Old);
+commit_write([H|R], Tid, Storage, Tab, K, Obj, Old)
   when element(1, H) == index ->
-    mnesia_index:add_index(H, Tab, K, Obj, Old),
-    commit_write(R, Tid, Tab, K, Obj, Old).
+    mnesia_index:add_index(H, Storage, Tab, K, Obj, Old),
+    commit_write(R, Tid, Storage, Tab, K, Obj, Old).
 
-commit_update([], _, _, _, _, _) -> ok;
-commit_update([{checkpoints, CpList}|R], Tid, Tab, K, Obj, _) ->
+commit_update([], _, _, _, _, _, _) -> ok;
+commit_update([{checkpoints, CpList}|R], Tid, Storage, Tab, K, Obj, _) ->
     Old = mnesia_checkpoint:tm_retain(Tid, Tab, K, write, CpList),
-    commit_update(R, Tid, Tab, K, Obj, Old);
-commit_update([H|R], Tid, Tab, K, Obj, Old)
+    commit_update(R, Tid, Storage, Tab, K, Obj, Old);
+commit_update([H|R], Tid, Storage, Tab, K, Obj, Old)
   when element(1, H) == subscribers ->
     mnesia_subscr:report_table_event(H, Tab, Tid, Obj, write, Old),
-    commit_update(R, Tid, Tab, K, Obj, Old);
-commit_update([H|R], Tid, Tab, K, Obj, Old)
+    commit_update(R, Tid, Storage, Tab, K, Obj, Old);
+commit_update([H|R], Tid,Storage,  Tab, K, Obj, Old)
   when element(1, H) == index ->
-    mnesia_index:add_index(H, Tab, K, Obj, Old),
-    commit_update(R, Tid, Tab, K, Obj, Old).
+    mnesia_index:add_index(H, Storage, Tab, K, Obj, Old),
+    commit_update(R, Tid, Storage, Tab, K, Obj, Old).
 
-commit_delete([], _, _, _, _, _) ->  ok;
-commit_delete([{checkpoints, CpList}|R], Tid, Tab, K, Obj, _) ->
+commit_delete([], _, _, _, _, _, _) ->  ok;
+commit_delete([{checkpoints, CpList}|R], Tid, Storage, Tab, K, Obj, _) ->
     Old = mnesia_checkpoint:tm_retain(Tid, Tab, K, delete, CpList),
-    commit_delete(R, Tid, Tab, K, Obj, Old);
-commit_delete([H|R], Tid, Tab, K, Obj, Old)
+    commit_delete(R, Tid, Storage, Tab, K, Obj, Old);
+commit_delete([H|R], Tid, Storage, Tab, K, Obj, Old)
   when element(1, H) == subscribers ->
     mnesia_subscr:report_table_event(H, Tab, Tid, Obj, delete, Old),
-    commit_delete(R, Tid, Tab, K, Obj, Old);
-commit_delete([H|R], Tid, Tab, K, Obj, Old)
+    commit_delete(R, Tid, Storage, Tab, K, Obj, Old);
+commit_delete([H|R], Tid, Storage, Tab, K, Obj, Old)
   when element(1, H) == index ->
-    mnesia_index:delete_index(H, Tab, K),
-    commit_delete(R, Tid, Tab, K, Obj, Old).
+    mnesia_index:delete_index(H, Storage, Tab, K),
+    commit_delete(R, Tid, Storage, Tab, K, Obj, Old).
 
 commit_del_object([], _, _, _, _, _) -> ok;
-commit_del_object([{checkpoints, CpList}|R], Tid, Tab, K, Obj, _) ->
-    Old = mnesia_checkpoint:tm_retain(Tid, Tab, K, delete_object, CpList),
-    commit_del_object(R, Tid, Tab, K, Obj, Old);
-commit_del_object([H|R], Tid, Tab, K, Obj, Old)
-  when element(1, H) == subscribers ->
-    mnesia_subscr:report_table_event(H, Tab, Tid, Obj, delete_object, Old),
-    commit_del_object(R, Tid, Tab, K, Obj, Old);
-commit_del_object([H|R], Tid, Tab, K, Obj, Old)
-  when element(1, H) == index ->
-    mnesia_index:del_object_index(H, Tab, K, Obj, Old),
-    commit_del_object(R, Tid, Tab, K, Obj, Old).
-
-commit_clear([], _, _, _, _) ->  ok;
-commit_clear([{checkpoints, CpList}|R], Tid, Tab, K, Obj) ->
+commit_del_object([{checkpoints, CpList}|R], Tid, Storage, Tab, K, Obj) ->
+    mnesia_checkpoint:tm_retain(Tid, Tab, K, delete_object, CpList),
+    commit_del_object(R, Tid, Storage, Tab, K, Obj);
+commit_del_object([H|R], Tid, Storage, Tab, K, Obj) when element(1, H) == subscribers ->
+    mnesia_subscr:report_table_event(H, Tab, Tid, Obj, delete_object),
+    commit_del_object(R, Tid, Storage, Tab, K, Obj);
+commit_del_object([H|R], Tid, Storage, Tab, K, Obj) when element(1, H) == index ->
+    mnesia_index:del_object_index(H, Storage, Tab, K, Obj),
+    commit_del_object(R, Tid, Storage, Tab, K, Obj).
+
+commit_clear([], _, _, _, _, _) ->  ok;
+commit_clear([{checkpoints, CpList}|R], Tid, Storage, Tab, K, Obj) ->
     mnesia_checkpoint:tm_retain(Tid, Tab, K, clear_table, CpList),
-    commit_clear(R, Tid, Tab, K, Obj);
-commit_clear([H|R], Tid, Tab, K, Obj)
+    commit_clear(R, Tid, Storage, Tab, K, Obj);
+commit_clear([H|R], Tid, Storage, Tab, K, Obj)
   when element(1, H) == subscribers ->
     mnesia_subscr:report_table_event(H, Tab, Tid, Obj, clear_table, undefined),
-    commit_clear(R, Tid, Tab, K, Obj);
-commit_clear([H|R], Tid, Tab, K, Obj)
+    commit_clear(R, Tid, Storage, Tab, K, Obj);
+commit_clear([H|R], Tid, Storage, Tab, K, Obj)
   when element(1, H) == index ->
     mnesia_index:clear_index(H, Tab, K, Obj),
-    commit_clear(R, Tid, Tab, K, Obj).
+    commit_clear(R, Tid, Storage, Tab, K, Obj).
 
 do_snmp(_, []) ->   ok;
-do_snmp(Tid, [Head | Tail]) ->
-    case catch mnesia_snmp_hook:update(Head) of
-	{'EXIT', Reason} ->
+do_snmp(Tid, [Head|Tail]) ->
+    try mnesia_snmp_hook:update(Head)
+    catch _:Reason ->
 	    %% This should only happen when we recently have
 	    %% deleted our local replica or recently deattached
 	    %% the snmp table
-
+	    ST = erlang:get_stacktrace(),
 	    verbose("do_snmp in ~w failed: ~p -> {'EXIT', ~p}~n",
-		    [Tid, Head, Reason]);
-	ok ->
-	    ignore
+		    [Tid, Head, {Reason, ST}])
     end,
     do_snmp(Tid, Tail).
 
-commit_nodes([C | Tail], AccD, AccR)
-        when C#commit.disc_copies == [],
-             C#commit.disc_only_copies  == [],
-             C#commit.schema_ops == [] ->
-    commit_nodes(Tail, AccD, [C#commit.node | AccR]);
 commit_nodes([C | Tail], AccD, AccR) ->
-    commit_nodes(Tail, [C#commit.node | AccD], AccR);
+    case C of
+	#commit{disc_copies=[], disc_only_copies=[], schema_ops=[], ext=Ext} ->
+	    case lists:keyfind(ext_copies, 1, Ext) of
+		false -> commit_nodes(Tail, AccD, [C#commit.node | AccR]);
+		_ -> commit_nodes(Tail, [C#commit.node | AccD], AccR)
+	    end;
+	_ ->
+	    commit_nodes(Tail, [C#commit.node | AccD], AccR)
+    end;
 commit_nodes([], AccD, AccR) ->
     {AccD, AccR}.
 
 commit_decision(D, [C | Tail], AccD, AccR) ->
     N = C#commit.node,
     {D2, Tail2} =
-	case C#commit.schema_ops of
-	    [] when C#commit.disc_copies == [],
-		    C#commit.disc_only_copies  == [] ->
-		commit_decision(D, Tail, AccD, [N | AccR]);
-	    [] ->
+	case C of
+	    #commit{disc_copies=[], disc_only_copies=[], schema_ops=[], ext=Ext} ->
+		case lists:keyfind(ext_copies, 1, Ext) of
+		    false -> commit_decision(D, Tail, AccD, [N | AccR]);
+		    _     -> commit_decision(D, Tail, [N | AccD], AccR)
+		end;
+	    #commit{schema_ops=[]} ->
 		commit_decision(D, Tail, [N | AccD], AccR);
-	    Ops ->
+	    #commit{schema_ops=Ops} ->
 		case ram_only_ops(N, Ops) of
-		    true ->
-			commit_decision(D, Tail, AccD, [N | AccR]);
-		    false ->
-			commit_decision(D, Tail, [N | AccD], AccR)
+		    true ->  commit_decision(D, Tail, AccD, [N | AccR]);
+		    false -> commit_decision(D, Tail, [N | AccD], AccR)
 		end
 	end,
     {D2, [C#commit{decision = D2} | Tail2]};
@@ -1975,7 +1978,7 @@ sync_send_dirty(Tid, [Head | Tail], Tab, WaitFor) ->
 	    Res =  do_dirty(Tid, Head),
 	    {WF, Res};
 	true ->
-    	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, Head, Tab}},
+	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, ext_format(Head), Tab}},
 	    sync_send_dirty(Tid, Tail, Tab, [Node | WaitFor])
     end;
 sync_send_dirty(_Tid, [], _Tab, WaitFor) ->
@@ -1994,11 +1997,11 @@ async_send_dirty(Tid, [Head | Tail], Tab, ReadNode, WaitFor, Res) ->
 	    NewRes =  do_dirty(Tid, Head),
 	    async_send_dirty(Tid, Tail, Tab, ReadNode, WaitFor, NewRes);
 	ReadNode == Node ->
-	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, Head, Tab}},
+	    {?MODULE, Node} ! {self(), {sync_dirty, Tid, ext_format(Head), Tab}},
 	    NewRes = {'EXIT', {aborted, {node_not_running, Node}}},
 	    async_send_dirty(Tid, Tail, Tab, ReadNode, [Node | WaitFor], NewRes);
 	true ->
-	    {?MODULE, Node} ! {self(), {async_dirty, Tid, Head, Tab}},
+	    {?MODULE, Node} ! {self(), {async_dirty, Tid, ext_format(Head), Tab}},
 	    async_send_dirty(Tid, Tail, Tab, ReadNode, WaitFor, Res)
     end;
 async_send_dirty(_Tid, [], _Tab, _ReadNode, WaitFor, Res) ->
@@ -2055,23 +2058,29 @@ ask_commit(Protocol, Tid, [Head | Tail], DiscNs, RamNs, WaitFor, Local) ->
 	Node == node() ->
 	    ask_commit(Protocol, Tid, Tail, DiscNs, RamNs, WaitFor, Head);
 	true ->
-	    Bin = opt_term_to_binary(Protocol, Head, DiscNs++RamNs),
-	    Msg = {ask_commit, Protocol, Tid, Bin, DiscNs, RamNs},
+	    CR = ext_format(Head),
+	    Msg = {ask_commit, Protocol, Tid, CR, DiscNs, RamNs},
 	    {?MODULE, Node} ! {self(), Msg},
 	    ask_commit(Protocol, Tid, Tail, DiscNs, RamNs, [Node | WaitFor], Local)
     end;
 ask_commit(_Protocol, _Tid, [], _DiscNs, _RamNs, WaitFor, Local) ->
     {WaitFor, Local}.
 
-%% This used to test protocol conversion between mnesia-nodes
-%% but it is really dependent on the emulator version on the
-%% two nodes (if funs are sent which they are in transform table op).
-%% to be safe we let erts do the translation (many times maybe and thus
-%% slower but it works.
-% opt_term_to_binary(asym_trans, Head, Nodes) ->
-%     opt_term_to_binary(Nodes, Head);
-opt_term_to_binary(_Protocol, Head, _Nodes) ->
-    Head.
+ext_format(#commit{ext=[]}=CR) -> CR;
+ext_format(#commit{node=Node, ext=Ext}=CR) ->
+    case mnesia_monitor:needs_protocol_conversion(Node) of
+	true  ->
+	    case lists:keyfind(snmp, 1, Ext) of
+		false -> CR#commit{ext=[]};
+		{snmp, List} -> CR#commit{ext=List}
+	    end;
+	false -> CR
+    end.
+
+new_cr_format(#commit{ext=[]}=Cr) -> Cr;
+new_cr_format(#commit{ext=[{_,_}|_]}=Cr) -> Cr;
+new_cr_format(#commit{ext=Snmp}=Cr) ->
+    Cr#commit{ext=[{snmp,Snmp}]}.
 
 rec_all([Node | Tail], Tid, Res, Pids) ->
     receive
@@ -2090,7 +2099,7 @@ rec_all([Node | Tail], Tid, Res, Pids) ->
 	    %% Make sure that mnesia_tm knows it has died
 	    %% it may have been restarted
 	    Abort = {do_abort, {bad_commit, Node}},
-	    catch {?MODULE, Node} ! {Tid, Abort},
+	    ?SAFE({?MODULE, Node} ! {Tid, Abort}),
 	    rec_all(Tail, Tid, Abort, Pids)
     end;
 rec_all([], _Tid, Res, Pids) ->
@@ -2234,8 +2243,6 @@ reconfigure_coordinators(N, [{Tid, [Store | _]} | Coordinators]) ->
 		true ->
 		    send_mnesia_down(Tid, Store, N)
 	    end;
-	aborted ->
-	    ignore; % avoid spurious mnesia_down messages
 	_ ->
 	    %% Tell the coordinator about the mnesia_down
 	    send_mnesia_down(Tid, Store, N)