* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.120 2002/06/20 20:29:27 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.121 2002/07/12 18:43:16 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "access/heapam.h"
#include "catalog/catalog.h"
#include "catalog/catname.h"
+#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_language.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_trigger.h"
-#include "commands/comment.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "miscadmin.h"
MemoryContext per_tuple_context);
-void
-CreateTrigger(CreateTrigStmt *stmt)
+Oid
+CreateTrigger(CreateTrigStmt *stmt, bool forConstraint)
{
int16 tgtype;
int16 tgattr[FUNC_MAX_ARGS];
Oid fargtypes[FUNC_MAX_ARGS];
Oid funcoid;
Oid funclang;
+ Oid trigoid;
int found = 0;
int i;
char constrtrigname[NAMEDATALEN];
- char *constrname = "";
- Oid constrrelid = InvalidOid;
+ char *trigname;
+ char *constrname;
+ Oid constrrelid;
+ ObjectAddress myself,
+ referenced;
rel = heap_openrv(stmt->relation, AccessExclusiveLock);
aclcheck_error(aclresult, RelationGetRelationName(rel));
/*
- * If trigger is an RI constraint, use trigger name as constraint name
- * and build a unique trigger name instead.
+ * If trigger is an RI constraint, use specified trigger name as
+ * constraint name and build a unique trigger name instead.
+ * This is mainly for backwards compatibility with CREATE CONSTRAINT
+ * TRIGGER commands.
*/
if (stmt->isconstraint)
{
- constrname = stmt->trigname;
snprintf(constrtrigname, sizeof(constrtrigname),
"RI_ConstraintTrigger_%u", newoid());
- stmt->trigname = constrtrigname;
-
- if (stmt->constrrel != NULL)
- constrrelid = RangeVarGetRelid(stmt->constrrel, false);
- else
- constrrelid = InvalidOid;
+ trigname = constrtrigname;
+ constrname = stmt->trigname;
}
+ else
+ {
+ trigname = stmt->trigname;
+ constrname = "";
+ }
+
+ if (stmt->constrrel != NULL)
+ constrrelid = RangeVarGetRelid(stmt->constrrel, false);
+ else
+ constrrelid = InvalidOid;
TRIGGER_CLEAR_TYPE(tgtype);
if (stmt->before)
{
Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
- if (namestrcmp(&(pg_trigger->tgname), stmt->trigname) == 0)
+ if (namestrcmp(&(pg_trigger->tgname), trigname) == 0)
elog(ERROR, "CreateTrigger: trigger %s already defined on relation %s",
- stmt->trigname, stmt->relation->relname);
+ trigname, stmt->relation->relname);
found++;
}
systable_endscan(tgscan);
values[Anum_pg_trigger_tgrelid - 1] = ObjectIdGetDatum(RelationGetRelid(rel));
values[Anum_pg_trigger_tgname - 1] = DirectFunctionCall1(namein,
- CStringGetDatum(stmt->trigname));
+ CStringGetDatum(trigname));
values[Anum_pg_trigger_tgfoid - 1] = ObjectIdGetDatum(funcoid);
values[Anum_pg_trigger_tgtype - 1] = Int16GetDatum(tgtype);
values[Anum_pg_trigger_tgenabled - 1] = BoolGetDatum(true);
values[Anum_pg_trigger_tgisconstraint - 1] = BoolGetDatum(stmt->isconstraint);
- values[Anum_pg_trigger_tgconstrname - 1] = PointerGetDatum(constrname);
+ values[Anum_pg_trigger_tgconstrname - 1] = DirectFunctionCall1(namein,
+ CStringGetDatum(constrname));
values[Anum_pg_trigger_tgconstrrelid - 1] = ObjectIdGetDatum(constrrelid);
values[Anum_pg_trigger_tgdeferrable - 1] = BoolGetDatum(stmt->deferrable);
values[Anum_pg_trigger_tginitdeferred - 1] = BoolGetDatum(stmt->initdeferred);
/*
* Insert tuple into pg_trigger.
*/
- simple_heap_insert(tgrel, tuple);
+ trigoid = simple_heap_insert(tgrel, tuple);
+
CatalogOpenIndices(Num_pg_trigger_indices, Name_pg_trigger_indices, idescs);
CatalogIndexInsert(idescs, Num_pg_trigger_indices, tgrel, tuple);
CatalogCloseIndices(Num_pg_trigger_indices, idescs);
+
+ myself.classId = RelationGetRelid(tgrel);
+ myself.objectId = trigoid;
+ myself.objectSubId = 0;
+
heap_freetuple(tuple);
heap_close(tgrel, RowExclusiveLock);
stmt->relation->relname);
((Form_pg_class) GETSTRUCT(tuple))->reltriggers = found + 1;
+
simple_heap_update(pgrel, &tuple->t_self, tuple);
+
CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs);
CatalogIndexInsert(ridescs, Num_pg_class_indices, pgrel, tuple);
CatalogCloseIndices(Num_pg_class_indices, ridescs);
+
heap_freetuple(tuple);
heap_close(pgrel, RowExclusiveLock);
* upcoming CommandCounterIncrement...
*/
+ /*
+ * Record dependencies for trigger. Always place a normal dependency
+ * on the function. If we are doing this in response to an explicit
+ * CREATE TRIGGER command, also make trigger be auto-dropped if its
+ * relation is dropped or if the FK relation is dropped. (Auto drop
+ * is compatible with our pre-7.3 behavior.) If the trigger is being
+ * made for a constraint, we can skip the relation links; the dependency
+ * on the constraint will indirectly depend on the relations.
+ */
+ referenced.classId = RelOid_pg_proc;
+ referenced.objectId = funcoid;
+ referenced.objectSubId = 0;
+ recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
+
+ if (!forConstraint)
+ {
+ referenced.classId = RelOid_pg_class;
+ referenced.objectId = RelationGetRelid(rel);
+ referenced.objectSubId = 0;
+ recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
+ if (constrrelid != InvalidOid)
+ {
+ referenced.classId = RelOid_pg_class;
+ referenced.objectId = constrrelid;
+ referenced.objectSubId = 0;
+ recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
+ }
+ }
+
/* Keep lock on target rel until end of xact */
heap_close(rel, NoLock);
+
+ return trigoid;
}
/*
* DropTrigger - drop an individual trigger by name
*/
void
-DropTrigger(Oid relid, const char *trigname)
+DropTrigger(Oid relid, const char *trigname, DropBehavior behavior)
+{
+ Relation tgrel;
+ ScanKeyData skey[2];
+ SysScanDesc tgscan;
+ HeapTuple tup;
+ ObjectAddress object;
+
+ /*
+ * Find the trigger, verify permissions, set up object address
+ */
+ tgrel = heap_openr(TriggerRelationName, AccessShareLock);
+
+ ScanKeyEntryInitialize(&skey[0], 0x0,
+ Anum_pg_trigger_tgrelid, F_OIDEQ,
+ ObjectIdGetDatum(relid));
+
+ ScanKeyEntryInitialize(&skey[1], 0x0,
+ Anum_pg_trigger_tgname, F_NAMEEQ,
+ CStringGetDatum(trigname));
+
+ tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
+ SnapshotNow, 2, skey);
+
+ tup = systable_getnext(tgscan);
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "DropTrigger: there is no trigger %s on relation %s",
+ trigname, get_rel_name(relid));
+
+ if (!pg_class_ownercheck(relid, GetUserId()))
+ aclcheck_error(ACLCHECK_NOT_OWNER, get_rel_name(relid));
+
+ object.classId = RelationGetRelid(tgrel);
+ object.objectId = tup->t_data->t_oid;
+ object.objectSubId = 0;
+
+ systable_endscan(tgscan);
+ heap_close(tgrel, AccessShareLock);
+
+ /*
+ * Do the deletion
+ */
+ performDeletion(&object, behavior);
+}
+
+/*
+ * Guts of trigger deletion.
+ */
+void
+RemoveTriggerById(Oid trigOid)
{
- Relation rel;
Relation tgrel;
SysScanDesc tgscan;
- ScanKeyData key;
+ ScanKeyData skey[1];
+ HeapTuple tup;
+ Oid relid;
+ Relation rel;
Relation pgrel;
HeapTuple tuple;
+ Form_pg_class classForm;
Relation ridescs[Num_pg_class_indices];
- int remaining = 0;
- int found = 0;
+
+ tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
+
+ /*
+ * Find the trigger to delete.
+ */
+ ScanKeyEntryInitialize(&skey[0], 0x0,
+ ObjectIdAttributeNumber, F_OIDEQ,
+ ObjectIdGetDatum(trigOid));
+
+ tgscan = systable_beginscan(tgrel, TriggerOidIndex, true,
+ SnapshotNow, 1, skey);
+
+ tup = systable_getnext(tgscan);
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "RemoveTriggerById: Trigger %u does not exist",
+ trigOid);
+
+ /*
+ * Open and exclusive-lock the relation the trigger belongs to.
+ */
+ relid = ((Form_pg_trigger) GETSTRUCT(tup))->tgrelid;
rel = heap_open(relid, AccessExclusiveLock);
elog(ERROR, "DropTrigger: can't drop trigger for system relation %s",
RelationGetRelationName(rel));
- if (!pg_class_ownercheck(relid, GetUserId()))
- aclcheck_error(ACLCHECK_NOT_OWNER, RelationGetRelationName(rel));
-
/*
- * Search pg_trigger, delete target trigger, count remaining triggers
- * for relation. (Although we could fetch and delete the target
- * trigger directly, we'd still have to scan the remaining triggers,
- * so we may as well do both in one indexscan.)
- *
- * Note this is OK only because we have AccessExclusiveLock on the rel,
- * so no one else is creating/deleting triggers on this rel at the same
- * time.
+ * Delete the pg_trigger tuple.
*/
- tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
- ScanKeyEntryInitialize(&key, 0,
- Anum_pg_trigger_tgrelid,
- F_OIDEQ,
- ObjectIdGetDatum(relid));
- tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
- SnapshotNow, 1, &key);
- while (HeapTupleIsValid(tuple = systable_getnext(tgscan)))
- {
- Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tuple);
+ simple_heap_delete(tgrel, &tup->t_self);
- if (namestrcmp(&(pg_trigger->tgname), trigname) == 0)
- {
- /* Delete any comments associated with this trigger */
- DeleteComments(tuple->t_data->t_oid, RelationGetRelid(tgrel));
-
- simple_heap_delete(tgrel, &tuple->t_self);
- found++;
- }
- else
- remaining++;
- }
systable_endscan(tgscan);
heap_close(tgrel, RowExclusiveLock);
- if (found == 0)
- elog(ERROR, "DropTrigger: there is no trigger %s on relation %s",
- trigname, RelationGetRelationName(rel));
- if (found > 1) /* shouldn't happen */
- elog(NOTICE, "DropTrigger: found (and deleted) %d triggers %s on relation %s",
- found, trigname, RelationGetRelationName(rel));
-
/*
* Update relation's pg_class entry. Crucial side-effect: other
* backends (and this one too!) are sent SI message to make them
* rebuild relcache entries.
+ *
+ * Note this is OK only because we have AccessExclusiveLock on the rel,
+ * so no one else is creating/deleting triggers on this rel at the same
+ * time.
*/
pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
tuple = SearchSysCacheCopy(RELOID,
if (!HeapTupleIsValid(tuple))
elog(ERROR, "DropTrigger: relation %s not found in pg_class",
RelationGetRelationName(rel));
+ classForm = (Form_pg_class) GETSTRUCT(tuple);
+
+ if (classForm->reltriggers == 0)
+ elog(ERROR, "DropTrigger: relation %s has reltriggers = 0",
+ RelationGetRelationName(rel));
+ classForm->reltriggers--;
- ((Form_pg_class) GETSTRUCT(tuple))->reltriggers = remaining;
simple_heap_update(pgrel, &tuple->t_self, tuple);
+
CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs);
CatalogIndexInsert(ridescs, Num_pg_class_indices, pgrel, tuple);
CatalogCloseIndices(Num_pg_class_indices, ridescs);
+
heap_freetuple(tuple);
+
heap_close(pgrel, RowExclusiveLock);
- /* Keep lock on target rel until end of xact */
+ /* Keep lock on trigger's rel until end of xact */
heap_close(rel, NoLock);
}
-/*
- * Remove all triggers for a relation that's being deleted.
- */
-void
-RelationRemoveTriggers(Relation rel)
-{
- Relation tgrel;
- SysScanDesc tgscan;
- ScanKeyData key;
- HeapTuple tup;
- bool found = false;
-
- tgrel = heap_openr(TriggerRelationName, RowExclusiveLock);
- ScanKeyEntryInitialize(&key, 0,
- Anum_pg_trigger_tgrelid,
- F_OIDEQ,
- ObjectIdGetDatum(RelationGetRelid(rel)));
- tgscan = systable_beginscan(tgrel, TriggerRelidNameIndex, true,
- SnapshotNow, 1, &key);
-
- while (HeapTupleIsValid(tup = systable_getnext(tgscan)))
- {
- /* Delete any comments associated with this trigger */
- DeleteComments(tup->t_data->t_oid, RelationGetRelid(tgrel));
-
- simple_heap_delete(tgrel, &tup->t_self);
-
- found = true;
- }
-
- systable_endscan(tgscan);
-
- /*
- * If we deleted any triggers, must update pg_class entry and advance
- * command counter to make the updated entry visible. This is fairly
- * annoying, since we'e just going to drop the durn thing later, but
- * it's necessary to have a consistent state in case we do
- * CommandCounterIncrement() below --- if RelationBuildTriggers()
- * runs, it will complain otherwise. Perhaps RelationBuildTriggers()
- * shouldn't be so picky...
- */
- if (found)
- {
- Relation pgrel;
- Relation ridescs[Num_pg_class_indices];
-
- pgrel = heap_openr(RelationRelationName, RowExclusiveLock);
- tup = SearchSysCacheCopy(RELOID,
- ObjectIdGetDatum(RelationGetRelid(rel)),
- 0, 0, 0);
- if (!HeapTupleIsValid(tup))
- elog(ERROR, "RelationRemoveTriggers: relation %u not found in pg_class",
- RelationGetRelid(rel));
-
- ((Form_pg_class) GETSTRUCT(tup))->reltriggers = 0;
- simple_heap_update(pgrel, &tup->t_self, tup);
- CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, ridescs);
- CatalogIndexInsert(ridescs, Num_pg_class_indices, pgrel, tup);
- CatalogCloseIndices(Num_pg_class_indices, ridescs);
- heap_freetuple(tup);
- heap_close(pgrel, RowExclusiveLock);
- CommandCounterIncrement();
- }
-
- /*
- * Also drop all constraint triggers referencing this relation
- */
- ScanKeyEntryInitialize(&key, 0,
- Anum_pg_trigger_tgconstrrelid,
- F_OIDEQ,
- ObjectIdGetDatum(RelationGetRelid(rel)));
- tgscan = systable_beginscan(tgrel, TriggerConstrRelidIndex, true,
- SnapshotNow, 1, &key);
-
- while (HeapTupleIsValid(tup = systable_getnext(tgscan)))
- {
- Form_pg_trigger pg_trigger = (Form_pg_trigger) GETSTRUCT(tup);
-
- elog(NOTICE, "DROP TABLE implicitly drops referential integrity trigger from table \"%s\"",
- get_rel_name(pg_trigger->tgrelid));
-
- DropTrigger(pg_trigger->tgrelid, NameStr(pg_trigger->tgname));
-
- /*
- * Need to do a command counter increment here to show up new
- * pg_class.reltriggers in the next loop iteration (in case there
- * are multiple referential integrity action triggers for the same
- * FK table defined on the PK table).
- */
- CommandCounterIncrement();
- }
- systable_endscan(tgscan);
-
- heap_close(tgrel, RowExclusiveLock);
-}
-
/*
* renametrig - changes the name of a trigger on a relation
*
projects / postgresql / blobdiff