diff options
Diffstat (limited to 'src/backend/commands')
| -rw-r--r-- | src/backend/commands/Makefile | 4 | ||||
| -rw-r--r-- | src/backend/commands/constraint.c | 166 | ||||
| -rw-r--r-- | src/backend/commands/copy.c | 10 | ||||
| -rw-r--r-- | src/backend/commands/indexcmds.c | 12 | ||||
| -rw-r--r-- | src/backend/commands/tablecmds.c | 31 | ||||
| -rw-r--r-- | src/backend/commands/trigger.c | 64 |
6 files changed, 250 insertions, 37 deletions
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile index e455e62c9aa..29a29ab7f4c 100644 --- a/src/backend/commands/Makefile +++ b/src/backend/commands/Makefile @@ -4,7 +4,7 @@ # Makefile for backend/commands # # IDENTIFICATION -# $PostgreSQL: pgsql/src/backend/commands/Makefile,v 1.39 2008/12/19 16:25:17 petere Exp $ +# $PostgreSQL: pgsql/src/backend/commands/Makefile,v 1.40 2009/07/29 20:56:18 tgl Exp $ # #------------------------------------------------------------------------- @@ -13,7 +13,7 @@ top_builddir = ../../.. include $(top_builddir)/src/Makefile.global OBJS = aggregatecmds.o alter.o analyze.o async.o cluster.o comment.o \ - conversioncmds.o copy.o \ + constraint.o conversioncmds.o copy.o \ dbcommands.o define.o discard.o explain.o foreigncmds.o functioncmds.o \ indexcmds.o lockcmds.o operatorcmds.o opclasscmds.o \ portalcmds.o prepare.o proclang.o \ diff --git a/src/backend/commands/constraint.c b/src/backend/commands/constraint.c new file mode 100644 index 00000000000..42d4d4e1f9c --- /dev/null +++ b/src/backend/commands/constraint.c @@ -0,0 +1,166 @@ +/*------------------------------------------------------------------------- + * + * constraint.c + * PostgreSQL CONSTRAINT support code. + * + * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * $PostgreSQL: pgsql/src/backend/commands/constraint.c,v 1.1 2009/07/29 20:56:18 tgl Exp $ + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "catalog/index.h" +#include "commands/trigger.h" +#include "executor/executor.h" +#include "utils/builtins.h" +#include "utils/tqual.h" + + +/* + * unique_key_recheck - trigger function to do a deferred uniqueness check. + * + * This is invoked as an AFTER ROW trigger for both INSERT and UPDATE, + * for any rows recorded as potentially violating a deferrable unique + * constraint. + * + * This may be an end-of-statement check, a commit-time check, or a + * check triggered by a SET CONSTRAINTS command. + */ +Datum +unique_key_recheck(PG_FUNCTION_ARGS) +{ + TriggerData *trigdata = (TriggerData *) fcinfo->context; + const char *funcname = "unique_key_recheck"; + HeapTuple new_row; + ItemPointerData tmptid; + Relation indexRel; + IndexInfo *indexInfo; + EState *estate; + ExprContext *econtext; + TupleTableSlot *slot; + Datum values[INDEX_MAX_KEYS]; + bool isnull[INDEX_MAX_KEYS]; + + /* + * Make sure this is being called as an AFTER ROW trigger. Note: + * translatable error strings are shared with ri_triggers.c, so + * resist the temptation to fold the function name into them. + */ + if (!CALLED_AS_TRIGGER(fcinfo)) + ereport(ERROR, + (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), + errmsg("function \"%s\" was not called by trigger manager", + funcname))); + + if (!TRIGGER_FIRED_AFTER(trigdata->tg_event) || + !TRIGGER_FIRED_FOR_ROW(trigdata->tg_event)) + ereport(ERROR, + (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), + errmsg("function \"%s\" must be fired AFTER ROW", + funcname))); + + /* + * Get the new data that was inserted/updated. + */ + if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event)) + new_row = trigdata->tg_trigtuple; + else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event)) + new_row = trigdata->tg_newtuple; + else + { + ereport(ERROR, + (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED), + errmsg("function \"%s\" must be fired for INSERT or UPDATE", + funcname))); + new_row = NULL; /* keep compiler quiet */ + } + + /* + * If the new_row is now dead (ie, inserted and then deleted within our + * transaction), we can skip the check. However, we have to be careful, + * because this trigger gets queued only in response to index insertions; + * which means it does not get queued for HOT updates. The row we are + * called for might now be dead, but have a live HOT child, in which case + * we still need to make the uniqueness check. Therefore we have to use + * heap_hot_search, not just HeapTupleSatisfiesVisibility as is done in + * the comparable test in RI_FKey_check. + * + * This might look like just an optimization, because the index AM will + * make this identical test before throwing an error. But it's actually + * needed for correctness, because the index AM will also throw an error + * if it doesn't find the index entry for the row. If the row's dead then + * it's possible the index entry has also been marked dead, and even + * removed. + */ + tmptid = new_row->t_self; + if (!heap_hot_search(&tmptid, trigdata->tg_relation, SnapshotSelf, NULL)) + { + /* + * All rows in the HOT chain are dead, so skip the check. + */ + return PointerGetDatum(NULL); + } + + /* + * Open the index, acquiring a RowExclusiveLock, just as if we were + * going to update it. (This protects against possible changes of the + * index schema, not against concurrent updates.) + */ + indexRel = index_open(trigdata->tg_trigger->tgconstrindid, + RowExclusiveLock); + indexInfo = BuildIndexInfo(indexRel); + + /* + * The heap tuple must be put into a slot for FormIndexDatum. + */ + slot = MakeSingleTupleTableSlot(RelationGetDescr(trigdata->tg_relation)); + + ExecStoreTuple(new_row, slot, InvalidBuffer, false); + + /* + * Typically the index won't have expressions, but if it does we need + * an EState to evaluate them. + */ + if (indexInfo->ii_Expressions != NIL) + { + estate = CreateExecutorState(); + econtext = GetPerTupleExprContext(estate); + econtext->ecxt_scantuple = slot; + } + else + estate = NULL; + + /* + * Form the index values and isnull flags for the index entry that + * we need to check. + * + * Note: if the index uses functions that are not as immutable as they + * are supposed to be, this could produce an index tuple different from + * the original. The index AM can catch such errors by verifying that + * it finds a matching index entry with the tuple's TID. + */ + FormIndexDatum(indexInfo, slot, estate, values, isnull); + + /* + * Now do the uniqueness check. This is not a real insert; it is a + * check that the index entry that has already been inserted is unique. + */ + index_insert(indexRel, values, isnull, &(new_row->t_self), + trigdata->tg_relation, UNIQUE_CHECK_EXISTING); + + /* + * If that worked, then this index entry is unique, and we are done. + */ + if (estate != NULL) + FreeExecutorState(estate); + + ExecDropSingleTupleTableSlot(slot); + + index_close(indexRel, RowExclusiveLock); + + return PointerGetDatum(NULL); +} diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c index b41da6385db..21f7b94d546 100644 --- a/src/backend/commands/copy.c +++ b/src/backend/commands/copy.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.315 2009/07/25 17:04:19 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.316 2009/07/29 20:56:18 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -2130,6 +2130,8 @@ CopyFrom(CopyState cstate) if (!skip_tuple) { + List *recheckIndexes = NIL; + /* Place tuple in tuple slot */ ExecStoreTuple(tuple, slot, InvalidBuffer, false); @@ -2141,10 +2143,12 @@ CopyFrom(CopyState cstate) heap_insert(cstate->rel, tuple, mycid, hi_options, bistate); if (resultRelInfo->ri_NumIndices > 0) - ExecInsertIndexTuples(slot, &(tuple->t_self), estate, false); + recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self), + estate, false); /* AFTER ROW INSERT Triggers */ - ExecARInsertTriggers(estate, resultRelInfo, tuple); + ExecARInsertTriggers(estate, resultRelInfo, tuple, + recheckIndexes); /* * We count only tuples not suppressed by a BEFORE INSERT trigger; diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c index ef879a3df2b..96272ab998d 100644 --- a/src/backend/commands/indexcmds.c +++ b/src/backend/commands/indexcmds.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.186 2009/07/16 06:33:42 petere Exp $ + * $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.187 2009/07/29 20:56:18 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -87,6 +87,8 @@ static bool relationHasPrimaryKey(Relation rel); * 'primary': mark the index as a primary key in the catalogs. * 'isconstraint': index is for a PRIMARY KEY or UNIQUE constraint, * so build a pg_constraint entry for it. + * 'deferrable': constraint is DEFERRABLE. + * 'initdeferred': constraint is INITIALLY DEFERRED. * 'is_alter_table': this is due to an ALTER rather than a CREATE operation. * 'check_rights': check for CREATE rights in the namespace. (This should * be true except when ALTER is deleting/recreating an index.) @@ -107,6 +109,8 @@ DefineIndex(RangeVar *heapRelation, bool unique, bool primary, bool isconstraint, + bool deferrable, + bool initdeferred, bool is_alter_table, bool check_rights, bool skip_build, @@ -447,7 +451,8 @@ DefineIndex(RangeVar *heapRelation, indexRelationId = index_create(relationId, indexRelationName, indexRelationId, indexInfo, accessMethodId, tablespaceId, classObjectId, - coloptions, reloptions, primary, isconstraint, + coloptions, reloptions, primary, + isconstraint, deferrable, initdeferred, allowSystemTableMods, skip_build, concurrent); return; /* We're done, in the standard case */ @@ -465,7 +470,8 @@ DefineIndex(RangeVar *heapRelation, indexRelationId = index_create(relationId, indexRelationName, indexRelationId, indexInfo, accessMethodId, tablespaceId, classObjectId, - coloptions, reloptions, primary, isconstraint, + coloptions, reloptions, primary, + isconstraint, deferrable, initdeferred, allowSystemTableMods, true, concurrent); /* diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index e883e8ed91f..0d3e3bc1670 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.292 2009/07/28 02:56:30 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.293 2009/07/29 20:56:18 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -4391,6 +4391,8 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel, stmt->unique, stmt->primary, stmt->isconstraint, + stmt->deferrable, + stmt->initdeferred, true, /* is_alter_table */ check_rights, skip_build, @@ -4955,6 +4957,17 @@ transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid, indexStruct = (Form_pg_index) GETSTRUCT(indexTuple); if (indexStruct->indisprimary) { + /* + * Refuse to use a deferrable primary key. This is per SQL spec, + * and there would be a lot of interesting semantic problems if + * we tried to allow it. + */ + if (!indexStruct->indimmediate) + ereport(ERROR, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("cannot use a deferrable primary key for referenced table \"%s\"", + RelationGetRelationName(pkrel)))); + *indexOid = indexoid; break; } @@ -5040,11 +5053,12 @@ transformFkeyCheckAttrs(Relation pkrel, indexStruct = (Form_pg_index) GETSTRUCT(indexTuple); /* - * Must have the right number of columns; must be unique and not a - * partial index; forget it if there are any expressions, too + * Must have the right number of columns; must be unique (non + * deferrable) and not a partial index; forget it if there are any + * expressions, too */ if (indexStruct->indnatts == numattrs && - indexStruct->indisunique && + indexStruct->indisunique && indexStruct->indimmediate && heap_attisnull(indexTuple, Anum_pg_index_indpred) && heap_attisnull(indexTuple, Anum_pg_index_indexprs)) { @@ -5243,7 +5257,8 @@ CreateFKCheckTrigger(RangeVar *myRel, FkConstraint *fkconstraint, fk_trigger->constrrel = fkconstraint->pktable; fk_trigger->args = NIL; - (void) CreateTrigger(fk_trigger, constraintOid, indexOid, false); + (void) CreateTrigger(fk_trigger, constraintOid, indexOid, + "RI_ConstraintTrigger", false); /* Make changes-so-far visible */ CommandCounterIncrement(); @@ -5322,7 +5337,8 @@ createForeignKeyTriggers(Relation rel, FkConstraint *fkconstraint, } fk_trigger->args = NIL; - (void) CreateTrigger(fk_trigger, constraintOid, indexOid, false); + (void) CreateTrigger(fk_trigger, constraintOid, indexOid, + "RI_ConstraintTrigger", false); /* Make changes-so-far visible */ CommandCounterIncrement(); @@ -5373,7 +5389,8 @@ createForeignKeyTriggers(Relation rel, FkConstraint *fkconstraint, } fk_trigger->args = NIL; - (void) CreateTrigger(fk_trigger, constraintOid, indexOid, false); + (void) CreateTrigger(fk_trigger, constraintOid, indexOid, + "RI_ConstraintTrigger", false); } /* diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c index 0cc33aae6b6..b84731126a1 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 - * $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.249 2009/07/28 02:56:30 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.250 2009/07/29 20:56:18 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -63,7 +63,8 @@ static HeapTuple ExecCallTriggerFunc(TriggerData *trigdata, Instrumentation *instr, MemoryContext per_tuple_context); static void AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, - bool row_trigger, HeapTuple oldtup, HeapTuple newtup); + bool row_trigger, HeapTuple oldtup, HeapTuple newtup, + List *recheckIndexes); /* @@ -77,6 +78,10 @@ static void AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, * indexOid, if nonzero, is the OID of an index associated with the constraint. * We do nothing with this except store it into pg_trigger.tgconstrindid. * + * prefix is NULL for user-created triggers. For internally generated + * constraint triggers, it is a prefix string to use in building the + * trigger name. (stmt->trigname is the constraint name in such cases.) + * * If checkPermissions is true we require ACL_TRIGGER permissions on the * relation. If not, the caller already checked permissions. (This is * currently redundant with constraintOid being zero, but it's clearer to @@ -87,7 +92,7 @@ static void AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, */ Oid CreateTrigger(CreateTrigStmt *stmt, - Oid constraintOid, Oid indexOid, + Oid constraintOid, Oid indexOid, const char *prefix, bool checkPermissions) { int16 tgtype; @@ -216,20 +221,20 @@ CreateTrigger(CreateTrigStmt *stmt, trigoid = GetNewOid(tgrel); /* - * If trigger is for an RI constraint, the passed-in name is the - * constraint name; save that and build a unique trigger name to avoid - * collisions with user-selected trigger names. + * If trigger is for a constraint, stmt->trigname is the constraint + * name; save that and build a unique trigger name based on the supplied + * prefix, to avoid collisions with user-selected trigger names. */ - if (OidIsValid(constraintOid)) + if (prefix != NULL) { snprintf(constrtrigname, sizeof(constrtrigname), - "RI_ConstraintTrigger_%u", trigoid); + "%s_%u", prefix, trigoid); trigname = constrtrigname; constrname = stmt->trigname; } else if (stmt->isconstraint) { - /* constraint trigger: trigger name is also constraint name */ + /* user constraint trigger: trigger name is also constraint name */ trigname = stmt->trigname; constrname = stmt->trigname; } @@ -1650,7 +1655,7 @@ ExecASInsertTriggers(EState *estate, ResultRelInfo *relinfo) if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_INSERT] > 0) AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_INSERT, - false, NULL, NULL); + false, NULL, NULL, NIL); } HeapTuple @@ -1706,13 +1711,13 @@ ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo, void ExecARInsertTriggers(EState *estate, ResultRelInfo *relinfo, - HeapTuple trigtuple) + HeapTuple trigtuple, List *recheckIndexes) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; if (trigdesc && trigdesc->n_after_row[TRIGGER_EVENT_INSERT] > 0) AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_INSERT, - true, NULL, trigtuple); + true, NULL, trigtuple, recheckIndexes); } void @@ -1781,7 +1786,7 @@ ExecASDeleteTriggers(EState *estate, ResultRelInfo *relinfo) if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_DELETE] > 0) AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_DELETE, - false, NULL, NULL); + false, NULL, NULL, NIL); } bool @@ -1858,7 +1863,7 @@ ExecARDeleteTriggers(EState *estate, ResultRelInfo *relinfo, tupleid, NULL); AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_DELETE, - true, trigtuple, NULL); + true, trigtuple, NULL, NIL); heap_freetuple(trigtuple); } } @@ -1929,7 +1934,7 @@ ExecASUpdateTriggers(EState *estate, ResultRelInfo *relinfo) if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_UPDATE] > 0) AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE, - false, NULL, NULL); + false, NULL, NULL, NIL); } HeapTuple @@ -1999,7 +2004,8 @@ ExecBRUpdateTriggers(EState *estate, ResultRelInfo *relinfo, void ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo, - ItemPointer tupleid, HeapTuple newtuple) + ItemPointer tupleid, HeapTuple newtuple, + List *recheckIndexes) { TriggerDesc *trigdesc = relinfo->ri_TrigDesc; @@ -2009,7 +2015,7 @@ ExecARUpdateTriggers(EState *estate, ResultRelInfo *relinfo, tupleid, NULL); AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_UPDATE, - true, trigtuple, newtuple); + true, trigtuple, newtuple, recheckIndexes); heap_freetuple(trigtuple); } } @@ -2080,7 +2086,7 @@ ExecASTruncateTriggers(EState *estate, ResultRelInfo *relinfo) if (trigdesc && trigdesc->n_after_statement[TRIGGER_EVENT_TRUNCATE] > 0) AfterTriggerSaveEvent(relinfo, TRIGGER_EVENT_TRUNCATE, - false, NULL, NULL); + false, NULL, NULL, NIL); } @@ -3793,15 +3799,18 @@ AfterTriggerPendingOnRel(Oid relid) /* ---------- * AfterTriggerSaveEvent() * - * Called by ExecA[RS]...Triggers() to add the event to the queue. + * Called by ExecA[RS]...Triggers() to queue up the triggers that should + * be fired for an event. * - * NOTE: should be called only if we've determined that an event must - * be added to the queue. + * NOTE: this is called whenever there are any triggers associated with + * the event (even if they are disabled). This function decides which + * triggers actually need to be queued. * ---------- */ static void AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, bool row_trigger, - HeapTuple oldtup, HeapTuple newtup) + HeapTuple oldtup, HeapTuple newtup, + List *recheckIndexes) { Relation rel = relinfo->ri_RelationDesc; TriggerDesc *trigdesc = relinfo->ri_TrigDesc; @@ -3962,6 +3971,17 @@ AfterTriggerSaveEvent(ResultRelInfo *relinfo, int event, bool row_trigger, } /* + * If the trigger is a deferred unique constraint check trigger, + * only queue it if the unique constraint was potentially violated, + * which we know from index insertion time. + */ + if (trigger->tgfoid == F_UNIQUE_KEY_RECHECK) + { + if (!list_member_oid(recheckIndexes, trigger->tgconstrindid)) + continue; /* Uniqueness definitely not violated */ + } + + /* * Fill in event structure and add it to the current query's queue. */ new_shared.ats_event = |