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-rw-r--r--lib/mnesia/src/mnesia_index.erl27
1 files changed, 17 insertions, 10 deletions
diff --git a/lib/mnesia/src/mnesia_index.erl b/lib/mnesia/src/mnesia_index.erl
index 81ed5a8f1a..0c882c0df6 100644
--- a/lib/mnesia/src/mnesia_index.erl
+++ b/lib/mnesia/src/mnesia_index.erl
@@ -70,17 +70,24 @@ add_index(Index, 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) ->
+add_index2([{Pos, Ixt} |Tail], Type, 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);
+ OldRecs1 = case OldRecs0 of
+ undefined -> mnesia_lib:db_get(Tab, K);
+ _ -> OldRecs0
+ end,
+ IdxVal = element(Pos, Obj),
+ case [Old || Old <- OldRecs1, element(Pos, Old) =/= IdxVal] of
+ [] when OldRecs1 =:= [] -> %% Write
+ db_put(Ixt, {element(Pos, Obj), K}),
+ add_index2(Tail, Type, Tab, K, Obj, OldRecs0);
+ [] -> %% when OldRecs1 =/= [] Update without modifying index field
+ add_index2(Tail, Type, Tab, K, Obj, OldRecs0);
+ OldRecs -> %% Update
+ db_put(Ixt, {element(Pos, Obj), K}),
+ del_ixes(Ixt, OldRecs, Pos, K),
+ add_index2(Tail, Type, Tab, K, Obj, OldRecs0)
+ end;
add_index2([], _, _Tab, _K, _Obj, _) -> ok.
delete_index(Index, Tab, K) ->