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I found a corner case in which it is possible for RI_FKey_check's call

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of HeapTupleSatisfiesItself() to trigger a hint-bit update on the tuple:
if the row was updated or deleted by a subtransaction of my own transaction
that was later rolled back.  This cannot occur in pre-8.0 of course, so
the hint-bit patch applied a couple weeks ago is OK for existing releases.
But for 8.0 it seems we had better fix things so that RI_FKey_check can
pass the correct buffer number to HeapTupleSatisfiesItself.  Accordingly,
add fields to the TriggerData struct to carry the buffer ID(s) for the
old and new tuple(s).  There are other possible solutions but this one
seems cleanest; it will allow other AFTER-trigger functions to safely
do tqual.c calls if they want to.  Put new fields at end of struct so
that there is no API breakage.
This commit is contained in:
Tom Lane
2004-10-30 20:53:06 +00:00
parent 88868d4fbc
commit 80559fa9e9
5 changed files with 73 additions and 24 deletions
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42
src/backend/commands/trigger.c
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.173 2004/10/21 21:33:59 tgl Exp $
* $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.174 2004/10/30 20:52:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1192,8 +1192,10 @@ ExecBSInsertTriggers(EState *estate, ResultRelInfo *relinfo)
LocTriggerData.tg_event = TRIGGER_EVENT_INSERT |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
@ -1246,6 +1248,7 @@ ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
@ -1253,6 +1256,7 @@ ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigtuple = oldtuple = newtuple;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
@ -1305,8 +1309,10 @@ ExecBSDeleteTriggers(EState *estate, ResultRelInfo *relinfo)
LocTriggerData.tg_event = TRIGGER_EVENT_DELETE |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
@ -1365,6 +1371,7 @@ ExecBRDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
@ -1372,6 +1379,7 @@ ExecBRDeleteTriggers(EState *estate, ResultRelInfo *relinfo,
if (!trigger->tgenabled)
continue;
LocTriggerData.tg_trigtuple = trigtuple;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
@ -1434,8 +1442,10 @@ ExecBSUpdateTriggers(EState *estate, ResultRelInfo *relinfo)
LocTriggerData.tg_event = TRIGGER_EVENT_UPDATE |
TRIGGER_EVENT_BEFORE;
LocTriggerData.tg_relation = relinfo->ri_RelationDesc;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuple = NULL;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
for (i = 0; i < ntrigs; i++)
{
Trigger *trigger = &trigdesc->triggers[tgindx[i]];
@ -1509,6 +1519,8 @@ ExecBRUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
continue;
LocTriggerData.tg_trigtuple = trigtuple;
LocTriggerData.tg_newtuple = oldtuple = newtuple;
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
LocTriggerData.tg_trigger = trigger;
newtuple = ExecCallTriggerFunc(&LocTriggerData,
relinfo->ri_TrigFunctions + tgindx[i],
@ -1896,8 +1908,8 @@ AfterTriggerExecute(AfterTriggerEvent event,
HeapTupleData oldtuple;
HeapTupleData newtuple;
HeapTuple rettuple;
Buffer oldbuffer;
Buffer newbuffer;
Buffer oldbuffer = InvalidBuffer;
Buffer newbuffer = InvalidBuffer;
int tgindx;
/*
@ -1942,16 +1954,22 @@ AfterTriggerExecute(AfterTriggerEvent event,
case TRIGGER_EVENT_INSERT:
LocTriggerData.tg_trigtuple = &newtuple;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = newbuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
break;
case TRIGGER_EVENT_UPDATE:
LocTriggerData.tg_trigtuple = &oldtuple;
LocTriggerData.tg_newtuple = &newtuple;
LocTriggerData.tg_trigtuplebuf = oldbuffer;
LocTriggerData.tg_newtuplebuf = newbuffer;
break;
case TRIGGER_EVENT_DELETE:
LocTriggerData.tg_trigtuple = &oldtuple;
LocTriggerData.tg_newtuple = NULL;
LocTriggerData.tg_trigtuplebuf = oldbuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
break;
}
@ -1970,9 +1988,9 @@ AfterTriggerExecute(AfterTriggerEvent event,
/*
* Release buffers
*/
if (ItemPointerIsValid(&(event->ate_oldctid)))
if (oldbuffer != InvalidBuffer)
ReleaseBuffer(oldbuffer);
if (ItemPointerIsValid(&(event->ate_newctid)))
if (newbuffer != InvalidBuffer)
ReleaseBuffer(newbuffer);
}
@ -2916,6 +2934,14 @@ AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, bool row_trigger,
LocTriggerData.tg_trigtuple = oldtup;
LocTriggerData.tg_newtuple = newtup;
LocTriggerData.tg_trigger = trigger;
/*
* We do not currently know which buffers the passed tuples
* are in, but it does not matter because RI_FKey_keyequal_upd
* does not care. We could expand the API of this function
* if it becomes necessary to set these fields accurately.
*/
LocTriggerData.tg_trigtuplebuf = InvalidBuffer;
LocTriggerData.tg_newtuplebuf = InvalidBuffer;
if (RI_FKey_keyequal_upd(&LocTriggerData))
{