git.postgresql.org Git - postgresql.git/commitdiff

git projects / postgresql.git / commitdiff

Remove small inefficiency in ExecARDeleteTriggers/ExecARUpdateTriggers.

2021年3月31日 00:01:27 +0000 (20:01 -0400)

2021年3月31日 00:01:31 +0000 (20:01 -0400)

Whilst poking at nodeModifyTable.c, I chanced to notice that while
its calls to ExecBR*Triggers and ExecIR*Triggers are protected by
tests to see if there are any relevant triggers to fire, its calls
to ExecAR*Triggers are not; the latter functions do the equivalent
tests themselves. This seems possibly reasonable given the more
complex conditions involved, but what's less reasonable is that
the ExecAR* functions aren't careful to do no work when there is
no work to be done. ExecARInsertTriggers gets this right, but the
other two will both force creation of a slot that the query may
have no use for. ExecARUpdateTriggers additionally performed a
usually-useless ExecClearTuple() on that slot. This is probably
all pretty microscopic in real workloads, but a cycle shaved is a
cycle earned.

src/backend/commands/trigger.c patch | blob | blame | history

diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c

index 7383d5994ebedc2d831fc1da6e14a004e8aa2e7d..0ee318b3409910c4a0775cce6681c444fe1960d4 100644 (file)

--- a/src/backend/commands/trigger.c

+++ b/src/backend/commands/trigger.c

@@ -2546,11 +2546,12 @@ ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo,

TransitionCaptureState *transition_capture)

{

TriggerDesc *trigdesc = relinfo->ri_TrigDesc;

- TupleTableSlot *slot = ExecGetTriggerOldSlot(estate, relinfo);

if ((trigdesc && trigdesc->trig_delete_after_row) ||

(transition_capture && transition_capture->tcs_delete_old_table))

{

+ TupleTableSlot *slot = ExecGetTriggerOldSlot(estate, relinfo);

Assert(HeapTupleIsValid(fdw_trigtuple) ^ ItemPointerIsValid(tupleid));

if (fdw_trigtuple == NULL)

GetTupleForTrigger(estate,

@@ -2829,9 +2830,6 @@ ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo,

TransitionCaptureState *transition_capture)

{

TriggerDesc *trigdesc = relinfo->ri_TrigDesc;

- TupleTableSlot *oldslot = ExecGetTriggerOldSlot(estate, relinfo);

- ExecClearTuple(oldslot);

if ((trigdesc && trigdesc->trig_update_after_row) ||

(transition_capture &&

@@ -2844,6 +2842,8 @@ ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo,

* separately for DELETE and INSERT to capture transition table rows.

* In such case, either old tuple or new tuple can be NULL.

+ TupleTableSlot *oldslot = ExecGetTriggerOldSlot(estate, relinfo);

if (fdw_trigtuple == NULL && ItemPointerIsValid(tupleid))

GetTupleForTrigger(estate,

NULL,

@@ -2854,6 +2854,8 @@ ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo,

NULL);

else if (fdw_trigtuple != NULL)

ExecForceStoreHeapTuple(fdw_trigtuple, oldslot, false);

+ else

+ ExecClearTuple(oldslot);

AfterTriggerSaveEvent(estate, relinfo, TRIGGER_EVENT_UPDATE,

true, oldslot, newslot, recheckIndexes,

This is the main PostgreSQL git repository.

RSS Atom