Fire non-deferred AFTER triggers immediately upon query completion,

rather than when returning to the idle loop.  This makes no particular
difference for interactively-issued queries, but it makes a big difference
for queries issued within functions: trigger execution now occurs before
the calling function is allowed to proceed.  This responds to numerous
complaints about nonintuitive behavior of foreign key checking, such as
http://archives.postgresql.org/pgsql-bugs/2004-09/msg00020.php, and
appears to be required by the SQL99 spec.
Also take the opportunity to simplify the data structures used for the
pending-trigger list, rename them for more clarity, and squeeze out a
bit of space.

src/backend/commands/copy.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.230 2004/08/29 05:06:41 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.231 2004/09/10 18:39:56 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1610,6 +1610,11 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 		}
 	}
 
+	/*
+	 * Prepare to catch AFTER triggers.
+	 */
+	AfterTriggerBeginQuery();
+
 	/*
 	 * Check BEFORE STATEMENT insertion triggers. It's debateable whether
 	 * we should do this for COPY, since it's not really an "INSERT"
@@ -1974,6 +1979,11 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 	 */
 	ExecASInsertTriggers(estate, resultRelInfo);
 
+	/*
+	 * Handle queued AFTER triggers
+	 */
+	AfterTriggerEndQuery();
+
 	pfree(values);
 	pfree(nulls);
 

src/backend/commands/explain.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994-5, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.124 2004/08/29 05:06:41 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.125 2004/09/10 18:39:56 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,6 +18,7 @@
 #include "catalog/pg_type.h"
 #include "commands/explain.h"
 #include "commands/prepare.h"
+#include "commands/trigger.h"
 #include "executor/executor.h"
 #include "executor/instrument.h"
 #include "lib/stringinfo.h"
@@ -206,6 +207,10 @@ ExplainOnePlan(QueryDesc *queryDesc, ExplainStmt *stmt,
 
 	gettimeofday(&starttime, NULL);
 
+	/* If analyzing, we need to cope with queued triggers */
+	if (stmt->analyze)
+		AfterTriggerBeginQuery();
+
 	/* call ExecutorStart to prepare the plan for execution */
 	ExecutorStart(queryDesc, false, !stmt->analyze);
 
@@ -255,12 +260,16 @@ ExplainOnePlan(QueryDesc *queryDesc, ExplainStmt *stmt,
 	}
 
 	/*
-	 * Close down the query and free resources.  Include time for this in
-	 * the total runtime.
+	 * Close down the query and free resources; also run any queued
+	 * AFTER triggers.  Include time for this in the total runtime.
 	 */
 	gettimeofday(&starttime, NULL);
 
 	ExecutorEnd(queryDesc);
+
+	if (stmt->analyze)
+		AfterTriggerEndQuery();
+
 	FreeQueryDesc(queryDesc);
 
 	CommandCounterIncrement();

src/backend/commands/portalcmds.c

@@ -14,7 +14,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.33 2004/08/29 05:06:41 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.34 2004/09/10 18:39:56 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -273,6 +273,7 @@ PortalCleanup(Portal portal)
 			{
 				CurrentResourceOwner = portal->resowner;
 				ExecutorEnd(queryDesc);
+				/* we do not need AfterTriggerEndQuery() here */
 			}
 			PG_CATCH();
 			{
@@ -373,6 +374,7 @@ PersistHoldablePortal(Portal portal)
 		 */
 		portal->queryDesc = NULL;		/* prevent double shutdown */
 		ExecutorEnd(queryDesc);
+		/* we do not need AfterTriggerEndQuery() here */
 
 		/*
 		 * Reset the position in the result set: ideally, this could be