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| author | Alexander Korotkov <akorotkov@postgresql.org> | 2024-03-26 01:27:56 +0200 |
|---|---|---|
| committer | Alexander Korotkov <akorotkov@postgresql.org> | 2024-03-26 01:27:56 +0200 |
| commit | 87985cc9252296f11db3cacc155e8d710d2e9b9c (patch) | |
| tree | 4b0fbb6eebcce344a7ddc16b4aa8a467e5d2649e /src/include/commands/trigger.h | |
| parent | c7076ba6ad1c2dc2ed50496b7ec71daebfe5327c (diff) | |
| download | postgresql-87985cc9252296f11db3cacc155e8d710d2e9b9c.tar.gz postgresql-87985cc9252296f11db3cacc155e8d710d2e9b9c.zip | |
Allow locking updated tuples in tuple_update() and tuple_delete()
Currently, in read committed transaction isolation mode (default), we have the
following sequence of actions when tuple_update()/tuple_delete() finds
the tuple updated by the concurrent transaction.
1. Attempt to update/delete tuple with tuple_update()/tuple_delete(), which
returns TM_Updated.
2. Lock tuple with tuple_lock().
3. Re-evaluate plan qual (recheck if we still need to update/delete and
calculate the new tuple for update).
4. Second attempt to update/delete tuple with tuple_update()/tuple_delete().
This attempt should be successful, since the tuple was previously locked.
This commit eliminates step 2 by taking the lock during the first
tuple_update()/tuple_delete() call. The heap table access method saves some
effort by checking the updated tuple once instead of twice. Future
undo-based table access methods, which will start from the latest row version,
can immediately place a lock there.
Also, this commit makes tuple_update()/tuple_delete() optionally save the old
tuple into the dedicated slot. That saves efforts on re-fetching tuples in
certain cases.
The code in nodeModifyTable.c is simplified by removing the nested switch/case.
Discussion: https://postgr.es/m/CAPpHfdua-YFw3XTprfutzGp28xXLigFtzNbuFY8yPhqeq6X5kg%40mail.gmail.com
Reviewed-by: Aleksander Alekseev, Pavel Borisov, Vignesh C, Mason Sharp
Reviewed-by: Andres Freund, Chris Travers
Diffstat (limited to 'src/include/commands/trigger.h')
| -rw-r--r-- | src/include/commands/trigger.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/include/commands/trigger.h b/src/include/commands/trigger.h index 8a5a9fe6422..cb968d03ecd 100644 --- a/src/include/commands/trigger.h +++ b/src/include/commands/trigger.h @@ -216,8 +216,8 @@ extern bool ExecBRDeleteTriggers(EState *estate, TM_FailureData *tmfd); extern void ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo, - ItemPointer tupleid, HeapTuple fdw_trigtuple, + TupleTableSlot *slot, TransitionCaptureState *transition_capture, bool is_crosspart_update); extern bool ExecIRDeleteTriggers(EState *estate, @@ -240,8 +240,8 @@ extern void ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo, ResultRelInfo *src_partinfo, ResultRelInfo *dst_partinfo, - ItemPointer tupleid, HeapTuple fdw_trigtuple, + TupleTableSlot *oldslot, TupleTableSlot *newslot, List *recheckIndexes, TransitionCaptureState *transition_capture, |