diff options
| -rw-r--r-- | src/backend/commands/trigger.c | 5 | ||||
| -rw-r--r-- | src/backend/executor/execMain.c | 32 | ||||
| -rw-r--r-- | src/include/executor/executor.h | 4 |
3 files changed, 32 insertions, 9 deletions
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index 125a9d2063e..3a4818eeeb9 100644 --- a/src/backend/commands/trigger.c +++ b/src/backend/commands/trigger.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.136.2.3 2005/08/26 20:07:15 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.136.2.4 2006/01/12 21:49:40 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1385,7 +1385,8 @@ ltrmark:; epqslot = EvalPlanQual(estate, relinfo->ri_RangeTableIndex, &update_ctid, - update_xmax); + update_xmax, + cid); if (!TupIsNull(epqslot)) { *tid = update_ctid; diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c index b6684579f1b..400afb81d28 100644 --- a/src/backend/executor/execMain.c +++ b/src/backend/executor/execMain.c @@ -27,7 +27,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.180.2.3 2005/08/26 20:07:17 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.180.2.4 2006/01/12 21:49:40 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1056,7 +1056,8 @@ lnext: ; newSlot = EvalPlanQual(estate, erm->rti, &update_ctid, - update_xmax); + update_xmax, + estate->es_snapshot->curcid); if (!TupIsNull(newSlot)) { slot = newSlot; @@ -1336,7 +1337,8 @@ ldelete:; epqslot = EvalPlanQual(estate, resultRelInfo->ri_RangeTableIndex, &update_ctid, - update_xmax); + update_xmax, + estate->es_snapshot->curcid); if (!TupIsNull(epqslot)) { *tupleid = update_ctid; @@ -1476,7 +1478,8 @@ lreplace:; epqslot = EvalPlanQual(estate, resultRelInfo->ri_RangeTableIndex, &update_ctid, - update_xmax); + update_xmax, + estate->es_snapshot->curcid); if (!TupIsNull(epqslot)) { *tupleid = update_ctid; @@ -1626,6 +1629,7 @@ ExecConstraints(const char *caller, ResultRelInfo *resultRelInfo, * rti - rangetable index of table containing tuple * *tid - t_ctid from the outdated tuple (ie, next updated version) * priorXmax - t_xmax from the outdated tuple + * curCid - command ID of current command of my transaction * * *tid is also an output parameter: it's modified to hold the TID of the * latest version of the tuple (note this may be changed even on failure) @@ -1635,7 +1639,7 @@ ExecConstraints(const char *caller, ResultRelInfo *resultRelInfo, */ TupleTableSlot * EvalPlanQual(EState *estate, Index rti, - ItemPointer tid, TransactionId priorXmax) + ItemPointer tid, TransactionId priorXmax, CommandId curCid) { evalPlanQual *epq; EState *epqstate; @@ -1713,6 +1717,24 @@ EvalPlanQual(EState *estate, Index rti, } /* + * If tuple was inserted by our own transaction, we have to check + * cmin against curCid: cmin >= curCid means our command cannot + * see the tuple, so we should ignore it. Without this we are + * open to the "Halloween problem" of indefinitely re-updating + * the same tuple. (We need not check cmax because + * HeapTupleSatisfiesDirty will consider a tuple deleted by + * our transaction dead, regardless of cmax.) We just checked + * that priorXmax == xmin, so we can test that variable instead + * of doing HeapTupleHeaderGetXmin again. + */ + if (TransactionIdIsCurrentTransactionId(priorXmax) && + HeapTupleHeaderGetCmin(tuple.t_data) >= curCid) + { + ReleaseBuffer(buffer); + return NULL; + } + + /* * We got tuple - now copy it for use by recheck query. */ copyTuple = heap_copytuple(&tuple); diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h index 734edc1ceda..5a98923627b 100644 --- a/src/include/executor/executor.h +++ b/src/include/executor/executor.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: executor.h,v 1.78.2.1 2005/08/26 20:07:17 tgl Exp $ + * $Id: executor.h,v 1.78.2.2 2006/01/12 21:49:41 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -55,7 +55,7 @@ extern void ExecutorEnd(QueryDesc *queryDesc, EState *estate); extern void ExecConstraints(const char *caller, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, EState *estate); extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti, - ItemPointer tid, TransactionId priorXmax); + ItemPointer tid, TransactionId priorXmax, CommandId curCid); /* * prototypes from functions in execProcnode.c |