diff options
Diffstat (limited to 'lib/mnesia/src')
| -rw-r--r-- | lib/mnesia/src/mnesia_index.erl | 27 |
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) -> |