SQL-language functions are now callable in ordinary fmgr contexts ...

for example, an SQL function can be used in a functional index.  (I make
no promises about speed, but it'll work ;-).)  Clean up and simplify
handling of functions returning sets.

src/backend/executor/execFlatten.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/Attic/execFlatten.c,v 1.12 2000/01/26 05:56:21 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/Attic/execFlatten.c,v 1.13 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,11 +36,12 @@ static bool FjoinBumpOuterNodes(TargetEntry *tlist, ExprContext *econtext,
 
 #endif
 
+
 Datum
 ExecEvalIter(Iter *iterNode,
 			 ExprContext *econtext,
-			 bool *resultIsNull,
-			 bool *iterIsDone)
+			 bool *isNull,
+			 ExprDoneCond *isDone)
 {
 	Node	   *expression;
 
@@ -52,14 +53,14 @@ ExecEvalIter(Iter *iterNode,
 	 * only worrying about postquel functions, c functions will come
 	 * later.
 	 */
-	return ExecEvalExpr(expression, econtext, resultIsNull, iterIsDone);
+	return ExecEvalExpr(expression, econtext, isNull, isDone);
 }
 
 void
 ExecEvalFjoin(TargetEntry *tlist,
 			  ExprContext *econtext,
 			  bool *isNullVect,
-			  bool *fj_isDone)
+			  ExprDoneCond *fj_isDone)
 {
 
 #ifdef SETS_FIXED
@@ -72,7 +73,7 @@ ExecEvalFjoin(TargetEntry *tlist,
 	BoolPtr		alwaysDone = fjNode->fj_alwaysDone;
 
 	if (fj_isDone)
-		*fj_isDone = false;
+		*fj_isDone = ExprMultipleResult;
 
 	/*
 	 * For the next tuple produced by the plan, we need to re-initialize

src/backend/executor/execScan.c

@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execScan.c,v 1.13 2000/07/17 03:04:53 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execScan.c,v 1.14 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -50,11 +50,10 @@ ExecScan(Scan *node,
 {
 	CommonScanState *scanstate;
 	EState	   *estate;
+	ExprContext *econtext;
 	List	   *qual;
-	bool		isDone;
+	ExprDoneCond isDone;
 	TupleTableSlot *resultSlot;
-	ExprContext *econtext;
-	ProjectionInfo *projInfo;
 
 	/* ----------------
 	 *	Fetch data from node
@@ -65,13 +64,6 @@ ExecScan(Scan *node,
 	econtext = scanstate->cstate.cs_ExprContext;
 	qual = node->plan.qual;
 
-	/* ----------------
-	 *	Reset per-tuple memory context to free any expression evaluation
-	 *	storage allocated in the previous tuple cycle.
-	 * ----------------
-	 */
-	ResetExprContext(econtext);
-
 	/* ----------------
 	 *	Check to see if we're still projecting out tuples from a previous
 	 *	scan tuple (because there is a function-returning-set in the
@@ -80,14 +72,21 @@ ExecScan(Scan *node,
 	 */
 	if (scanstate->cstate.cs_TupFromTlist)
 	{
-		projInfo = scanstate->cstate.cs_ProjInfo;
-		resultSlot = ExecProject(projInfo, &isDone);
-		if (!isDone)
+		resultSlot = ExecProject(scanstate->cstate.cs_ProjInfo, &isDone);
+		if (isDone == ExprMultipleResult)
 			return resultSlot;
 		/* Done with that source tuple... */
 		scanstate->cstate.cs_TupFromTlist = false;
 	}
 
+	/* ----------------
+	 *	Reset per-tuple memory context to free any expression evaluation
+	 *	storage allocated in the previous tuple cycle.  Note this can't
+	 *	happen until we're done projecting out tuples from a scan tuple.
+	 * ----------------
+	 */
+	ResetExprContext(econtext);
+
 	/*
 	 * get a tuple from the access method loop until we obtain a tuple
 	 * which passes the qualification.
@@ -121,8 +120,6 @@ ExecScan(Scan *node,
 
 		/* ----------------
 		 *	check that the current tuple satisfies the qual-clause
-		 *	if our qualification succeeds then we may
-		 *	leave the loop.
 		 *
 		 * check for non-nil qual here to avoid a function call to
 		 * ExecQual() when the qual is nil ... saves only a few cycles,
@@ -130,7 +127,22 @@ ExecScan(Scan *node,
 		 * ----------------
 		 */
 		if (!qual || ExecQual(qual, econtext, false))
-			break;
+		{
+			/* ----------------
+			 *	Found a satisfactory scan tuple.
+			 *
+			 *	Form a projection tuple, store it in the result tuple
+			 *	slot and return it --- unless we find we can project no
+			 *	tuples from this scan tuple, in which case continue scan.
+			 * ----------------
+			 */
+			resultSlot = ExecProject(scanstate->cstate.cs_ProjInfo, &isDone);
+			if (isDone != ExprEndResult)
+			{
+				scanstate->cstate.cs_TupFromTlist = (isDone == ExprMultipleResult);
+				return resultSlot;
+			}
+		}
 
 		/* ----------------
 		 *	Tuple fails qual, so free per-tuple memory and try again.
@@ -138,18 +150,4 @@ ExecScan(Scan *node,
 		 */
 		ResetExprContext(econtext);
 	}
-
-	/* ----------------
-	 *	Found a satisfactory scan tuple.
-	 *
-	 *	Form a projection tuple, store it in the result tuple
-	 *	slot and return it.
-	 * ----------------
-	 */
-	projInfo = scanstate->cstate.cs_ProjInfo;
-
-	resultSlot = ExecProject(projInfo, &isDone);
-	scanstate->cstate.cs_TupFromTlist = !isDone;
-
-	return resultSlot;
 }

src/backend/executor/nodeAgg.c

@@ -34,7 +34,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.70 2000/07/17 03:04:53 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.71 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -451,7 +451,6 @@ ExecAgg(Agg *node)
 	TupleTableSlot *resultSlot;
 	HeapTuple	inputTuple;
 	int			aggno;
-	bool		isDone;
 	bool		isNull;
 
 	/* ---------------------
@@ -523,7 +522,7 @@ ExecAgg(Agg *node)
 				Datum		newVal;
 
 				newVal = ExecEvalExpr(aggref->target, econtext,
-									  &isNull, &isDone);
+									  &isNull, NULL);
 
 				if (aggref->aggdistinct)
 				{
@@ -677,8 +676,9 @@ ExecAgg(Agg *node)
 		/*
 		 * Form a projection tuple using the aggregate results and the
 		 * representative input tuple.	Store it in the result tuple slot.
+		 * Note we do not support aggregates returning sets ...
 		 */
-		resultSlot = ExecProject(projInfo, &isDone);
+		resultSlot = ExecProject(projInfo, NULL);
 
 		/*
 		 * If the completed tuple does not match the qualifications, it is

src/backend/executor/nodeGroup.c

@@ -15,7 +15,7 @@
  *	  locate group boundaries.
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeGroup.c,v 1.37 2000/07/12 02:37:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeGroup.c,v 1.38 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -73,7 +73,6 @@ ExecGroupEveryTuple(Group *node)
 	TupleTableSlot *outerslot;
 	ProjectionInfo *projInfo;
 	TupleTableSlot *resultSlot;
-	bool		isDone;
 
 	/* ---------------------
 	 *	get state info from node
@@ -163,7 +162,7 @@ ExecGroupEveryTuple(Group *node)
 	projInfo = grpstate->csstate.cstate.cs_ProjInfo;
 
 	econtext->ecxt_scantuple = grpstate->csstate.css_ScanTupleSlot;
-	resultSlot = ExecProject(projInfo, &isDone);
+	resultSlot = ExecProject(projInfo, NULL);
 
 	return resultSlot;
 }
@@ -185,7 +184,6 @@ ExecGroupOneTuple(Group *node)
 	TupleTableSlot *outerslot;
 	ProjectionInfo *projInfo;
 	TupleTableSlot *resultSlot;
-	bool		isDone;
 
 	/* ---------------------
 	 *	get state info from node
@@ -258,7 +256,7 @@ ExecGroupOneTuple(Group *node)
 				   grpstate->csstate.css_ScanTupleSlot,
 				   InvalidBuffer, false);
 	econtext->ecxt_scantuple = grpstate->csstate.css_ScanTupleSlot;
-	resultSlot = ExecProject(projInfo, &isDone);
+	resultSlot = ExecProject(projInfo, NULL);
 
 	/* save outerTuple if we are not done yet */
 	if (!grpstate->grp_done)

src/backend/executor/nodeHash.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
- *	$Id: nodeHash.c,v 1.51 2000/08/22 04:06:19 tgl Exp $
+ *	$Id: nodeHash.c,v 1.52 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -524,7 +524,6 @@ ExecHashGetBucket(HashJoinTable hashtable,
 	int			bucketno;
 	Datum		keyval;
 	bool		isNull;
-	bool		isDone;
 
 	/* ----------------
 	 *	Get the join attribute value of the tuple
@@ -535,8 +534,7 @@ ExecHashGetBucket(HashJoinTable hashtable,
 	 */
 	ResetExprContext(econtext);
 
-	keyval = ExecEvalExprSwitchContext(hashkey, econtext,
-									   &isNull, &isDone);
+	keyval = ExecEvalExprSwitchContext(hashkey, econtext, &isNull, NULL);
 
 	/* ------------------
 	 *	compute the hash function

src/backend/executor/nodeHashjoin.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.32 2000/07/17 03:04:53 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.33 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -55,6 +55,7 @@ ExecHashJoin(HashJoin *node)
 	TupleTableSlot *inntuple;
 	Node	   *outerVar;
 	ExprContext *econtext;
+	ExprDoneCond isDone;
 	HashJoinTable hashtable;
 	HeapTuple	curtuple;
 	TupleTableSlot *outerTupleSlot;
@@ -83,13 +84,6 @@ ExecHashJoin(HashJoin *node)
 	hashtable = hjstate->hj_HashTable;
 	econtext = hjstate->jstate.cs_ExprContext;
 
-	/* ----------------
-	 *	Reset per-tuple memory context to free any expression evaluation
-	 *	storage allocated in the previous tuple cycle.
-	 * ----------------
-	 */
-	ResetExprContext(econtext);
-
 	/* ----------------
 	 *	Check to see if we're still projecting out tuples from a previous
 	 *	join tuple (because there is a function-returning-set in the
@@ -99,15 +93,22 @@ ExecHashJoin(HashJoin *node)
 	if (hjstate->jstate.cs_TupFromTlist)
 	{
 		TupleTableSlot *result;
-		bool		isDone;
 
 		result = ExecProject(hjstate->jstate.cs_ProjInfo, &isDone);
-		if (!isDone)
+		if (isDone == ExprMultipleResult)
 			return result;
 		/* Done with that source tuple... */
 		hjstate->jstate.cs_TupFromTlist = false;
 	}
 
+	/* ----------------
+	 *	Reset per-tuple memory context to free any expression evaluation
+	 *	storage allocated in the previous tuple cycle.  Note this can't
+	 *	happen until we're done projecting out tuples from a join tuple.
+	 * ----------------
+	 */
+	ResetExprContext(econtext);
+
 	/* ----------------
 	 *	if this is the first call, build the hash table for inner relation
 	 * ----------------
@@ -241,15 +242,15 @@ ExecHashJoin(HashJoin *node)
 			 */
 			if (ExecQual(qual, econtext, false))
 			{
-				ProjectionInfo *projInfo;
 				TupleTableSlot *result;
-				bool		isDone;
 
 				hjstate->jstate.cs_OuterTupleSlot = outerTupleSlot;
-				projInfo = hjstate->jstate.cs_ProjInfo;
-				result = ExecProject(projInfo, &isDone);
-				hjstate->jstate.cs_TupFromTlist = !isDone;
-				return result;
+				result = ExecProject(hjstate->jstate.cs_ProjInfo, &isDone);
+				if (isDone != ExprEndResult)
+				{
+					hjstate->jstate.cs_TupFromTlist = (isDone == ExprMultipleResult);
+					return result;
+				}
 			}
 		}
 

src/backend/executor/nodeIndexscan.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.53 2000/08/13 02:50:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.54 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -334,7 +334,6 @@ ExecIndexReScan(IndexScan *node, ExprContext *exprCtxt, Plan *parent)
 	Node	   *scanexpr;
 	Datum		scanvalue;
 	bool		isNull;
-	bool		isDone;
 
 	estate = node->scan.plan.state;
 	indexstate = node->indxstate;
@@ -411,14 +410,10 @@ ExecIndexReScan(IndexScan *node, ExprContext *exprCtxt, Plan *parent)
 						(Node *) get_rightop(clause) :
 						(Node *) get_leftop(clause);
 
-					/*
-					 * pass in isDone but ignore it.  We don't iterate in
-					 * quals
-					 */
 					scanvalue = ExecEvalExprSwitchContext(scanexpr,
 														  econtext,
 														  &isNull,
-														  &isDone);
+														  NULL);
 					scan_keys[j].sk_argument = scanvalue;
 					if (isNull)
 						scan_keys[j].sk_flags |= SK_ISNULL;

src/backend/executor/nodeMergejoin.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.36 2000/07/12 02:37:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.37 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -226,18 +226,16 @@ MergeCompare(List *eqQual, List *compareQual, ExprContext *econtext)
 	{
 		Datum		const_value;
 		bool		isNull;
-		bool		isDone;
 
 		/* ----------------
 		 *	 first test if our compare clause is satisfied.
 		 *	 if so then return true.
 		 *
 		 *	 A NULL result is considered false.
-		 *	 ignore isDone, don't iterate in quals.
 		 * ----------------
 		 */
 		const_value = ExecEvalExpr((Node *) lfirst(clause), econtext,
-								   &isNull, &isDone);
+								   &isNull, NULL);
 
 		if (DatumGetBool(const_value) && !isNull)
 		{
@@ -254,7 +252,7 @@ MergeCompare(List *eqQual, List *compareQual, ExprContext *econtext)
 		const_value = ExecEvalExpr((Node *) lfirst(eqclause),
 								   econtext,
 								   &isNull,
-								   &isDone);
+								   NULL);
 
 		if (! DatumGetBool(const_value) || isNull)
 			break;				/* return false */
@@ -447,13 +445,6 @@ ExecMergeJoin(MergeJoin *node)
 		innerSkipQual = mergestate->mj_OuterSkipQual;
 	}
 
-	/* ----------------
-	 *	Reset per-tuple memory context to free any expression evaluation
-	 *	storage allocated in the previous tuple cycle.
-	 * ----------------
-	 */
-	ResetExprContext(econtext);
-
 	/* ----------------
 	 *	Check to see if we're still projecting out tuples from a previous
 	 *	join tuple (because there is a function-returning-set in the
@@ -463,15 +454,23 @@ ExecMergeJoin(MergeJoin *node)
 	if (mergestate->jstate.cs_TupFromTlist)
 	{
 		TupleTableSlot *result;
-		bool		isDone;
+		ExprDoneCond	isDone;
 
 		result = ExecProject(mergestate->jstate.cs_ProjInfo, &isDone);
-		if (!isDone)
+		if (isDone == ExprMultipleResult)
 			return result;
 		/* Done with that source tuple... */
 		mergestate->jstate.cs_TupFromTlist = false;
 	}
 
+	/* ----------------
+	 *	Reset per-tuple memory context to free any expression evaluation
+	 *	storage allocated in the previous tuple cycle.  Note this can't
+	 *	happen until we're done projecting out tuples from a join tuple.
+	 * ----------------
+	 */
+	ResetExprContext(econtext);
+
 	/* ----------------
 	 *	ok, everything is setup.. let's go to work
 	 * ----------------
@@ -599,17 +598,19 @@ ExecMergeJoin(MergeJoin *node)
 					 *	projection tuple and return the slot containing it.
 					 * ----------------
 					 */
-					ProjectionInfo *projInfo;
 					TupleTableSlot *result;
-					bool		isDone;
+					ExprDoneCond isDone;
 
 					MJ_printf("ExecMergeJoin: **** returning tuple ****\n");
 
-					projInfo = mergestate->jstate.cs_ProjInfo;
+					result = ExecProject(mergestate->jstate.cs_ProjInfo,
+										 &isDone);
 
-					result = ExecProject(projInfo, &isDone);
-					mergestate->jstate.cs_TupFromTlist = !isDone;
-					return result;
+					if (isDone != ExprEndResult)
+					{
+						mergestate->jstate.cs_TupFromTlist = (isDone == ExprMultipleResult);
+						return result;
+					}
 				}
 				break;
 

src/backend/executor/nodeNestloop.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeNestloop.c,v 1.19 2000/08/13 02:50:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeNestloop.c,v 1.20 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -87,13 +87,6 @@ ExecNestLoop(NestLoop *node)
 	outerTupleSlot = nlstate->jstate.cs_OuterTupleSlot;
 	econtext->ecxt_outertuple = outerTupleSlot;
 
-	/* ----------------
-	 *	Reset per-tuple memory context to free any expression evaluation
-	 *	storage allocated in the previous tuple cycle.
-	 * ----------------
-	 */
-	ResetExprContext(econtext);
-
 	/* ----------------
 	 *	Check to see if we're still projecting out tuples from a previous
 	 *	join tuple (because there is a function-returning-set in the
@@ -103,15 +96,23 @@ ExecNestLoop(NestLoop *node)
 	if (nlstate->jstate.cs_TupFromTlist)
 	{
 		TupleTableSlot *result;
-		bool		isDone;
+		ExprDoneCond	isDone;
 
 		result = ExecProject(nlstate->jstate.cs_ProjInfo, &isDone);
-		if (!isDone)
+		if (isDone == ExprMultipleResult)
 			return result;
 		/* Done with that source tuple... */
 		nlstate->jstate.cs_TupFromTlist = false;
 	}
 
+	/* ----------------
+	 *	Reset per-tuple memory context to free any expression evaluation
+	 *	storage allocated in the previous tuple cycle.  Note this can't
+	 *	happen until we're done projecting out tuples from a join tuple.
+	 * ----------------
+	 */
+	ResetExprContext(econtext);
+
 	/* ----------------
 	 *	Ok, everything is setup for the join so now loop until
 	 *	we return a qualifying join tuple..
@@ -219,16 +220,18 @@ ExecNestLoop(NestLoop *node)
 			 *	using ExecProject().
 			 * ----------------
 			 */
-			ProjectionInfo *projInfo;
 			TupleTableSlot *result;
-			bool		isDone;
+			ExprDoneCond isDone;
 
 			ENL1_printf("qualification succeeded, projecting tuple");
 
-			projInfo = nlstate->jstate.cs_ProjInfo;
-			result = ExecProject(projInfo, &isDone);
-			nlstate->jstate.cs_TupFromTlist = !isDone;
-			return result;
+			result = ExecProject(nlstate->jstate.cs_ProjInfo, &isDone);
+
+			if (isDone != ExprEndResult)
+			{
+				nlstate->jstate.cs_TupFromTlist = (isDone == ExprMultipleResult);
+				return result;
+			}
 		}
 
 		/* ----------------

src/backend/executor/nodeResult.c

@@ -34,7 +34,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeResult.c,v 1.15 2000/07/17 03:04:53 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeResult.c,v 1.16 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -67,8 +67,7 @@ ExecResult(Result *node)
 	TupleTableSlot *resultSlot;
 	Plan	   *outerPlan;
 	ExprContext *econtext;
-	bool		isDone;
-	ProjectionInfo *projInfo;
+	ExprDoneCond isDone;
 
 	/* ----------------
 	 *	initialize the result node's state
@@ -77,13 +76,6 @@ ExecResult(Result *node)
 	resstate = node->resstate;
 	econtext = resstate->cstate.cs_ExprContext;
 
-	/* ----------------
-	 *	Reset per-tuple memory context to free any expression evaluation
-	 *	storage allocated in the previous tuple cycle.
-	 * ----------------
-	 */
-	ResetExprContext(econtext);
-
 	/* ----------------
 	 *	 check constant qualifications like (2 > 1), if not already done
 	 * ----------------
@@ -111,12 +103,20 @@ ExecResult(Result *node)
 	if (resstate->cstate.cs_TupFromTlist)
 	{
 		resultSlot = ExecProject(resstate->cstate.cs_ProjInfo, &isDone);
-		if (!isDone)
+		if (isDone == ExprMultipleResult)
 			return resultSlot;
 		/* Done with that source tuple... */
 		resstate->cstate.cs_TupFromTlist = false;
 	}
 
+	/* ----------------
+	 *	Reset per-tuple memory context to free any expression evaluation
+	 *	storage allocated in the previous tuple cycle.  Note this can't
+	 *	happen until we're done projecting out tuples from a scan tuple.
+	 * ----------------
+	 */
+	ResetExprContext(econtext);
+
 	/* ----------------
 	 *	if rs_done is true then it means that we were asked to return
 	 *	a constant tuple and we already did the last time ExecResult()
@@ -124,7 +124,7 @@ ExecResult(Result *node)
 	 *	Either way, now we are through.
 	 * ----------------
 	 */
-	if (!resstate->rs_done)
+	while (!resstate->rs_done)
 	{
 		outerPlan = outerPlan(node);
 
@@ -159,13 +159,18 @@ ExecResult(Result *node)
 		}
 
 		/* ----------------
-		 *	 form the result tuple using ExecProject(), and return it.
+		 *	 form the result tuple using ExecProject(), and return it
+		 *	 --- unless the projection produces an empty set, in which case
+		 *	 we must loop back to see if there are more outerPlan tuples.
 		 * ----------------
 		 */
-		projInfo = resstate->cstate.cs_ProjInfo;
-		resultSlot = ExecProject(projInfo, &isDone);
-		resstate->cstate.cs_TupFromTlist = !isDone;
-		return resultSlot;
+		resultSlot = ExecProject(resstate->cstate.cs_ProjInfo, &isDone);
+
+		if (isDone != ExprEndResult)
+		{
+			resstate->cstate.cs_TupFromTlist = (isDone == ExprMultipleResult);
+			return resultSlot;
+		}
 	}
 
 	return NULL;

src/backend/executor/nodeSubplan.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.26 2000/07/12 02:37:04 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.27 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,7 +40,6 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
 	MemoryContext oldcontext;
 	TupleTableSlot *slot;
 	Datum		result;
-	bool		isDone;
 	bool		found = false;	/* TRUE if got at least one subplan tuple */
 	List	   *lst;
 
@@ -67,9 +66,7 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
 			prm->value = ExecEvalExprSwitchContext((Node *) lfirst(pvar),
 												   econtext,
 												   &(prm->isnull),
-												   &isDone);
-			if (!isDone)
-				elog(ERROR, "ExecSubPlan: set values not supported for params");
+												   NULL);
 			pvar = lnext(pvar);
 		}
 		plan->chgParam = nconc(plan->chgParam, listCopy(node->parParam));
@@ -189,9 +186,7 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
 			 * Now we can eval the combining operator for this column.
 			 */
 			expresult = ExecEvalExprSwitchContext((Node *) expr, econtext,
-												  &expnull, &isDone);
-			if (!isDone)
-				elog(ERROR, "ExecSubPlan: set values not supported for combining operators");
+												  &expnull, NULL);
 
 			/*
 			 * Combine the result into the row result as appropriate.

src/backend/executor/nodeTidscan.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeTidscan.c,v 1.11 2000/08/03 19:19:30 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeTidscan.c,v 1.12 2000/08/24 03:29:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -38,7 +38,6 @@ TidListCreate(List *evalList, ExprContext *econtext, ItemPointer *tidList)
 	List	   *lst;
 	ItemPointer itemptr;
 	bool		isNull;
-	bool		isDone;
 	int			numTids = 0;
 
 	foreach(lst, evalList)
@@ -47,8 +46,8 @@ TidListCreate(List *evalList, ExprContext *econtext, ItemPointer *tidList)
 			DatumGetPointer(ExecEvalExprSwitchContext(lfirst(lst),
 													  econtext,
 													  &isNull,
-													  &isDone));
-		if (itemptr && ItemPointerIsValid(itemptr))
+													  NULL));
+		if (!isNull && itemptr && ItemPointerIsValid(itemptr))
 		{
 			tidList[numTids] = itemptr;
 			numTids++;

src/backend/optimizer/path/indxpath.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.93 2000/08/13 02:50:04 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.94 2000/08/24 03:29:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1380,9 +1380,8 @@ clause_pred_clause_test(Expr *predicate, Node *clause)
 							  copyObject(clause_const),
 							  copyObject(pred_const));
 
-#ifndef OMIT_PARTIAL_INDEX
 	test_result = ExecEvalExpr((Node *) test_expr, NULL, &isNull, NULL);
-#endif	 /* OMIT_PARTIAL_INDEX */
+
 	if (isNull)
 	{
 		elog(DEBUG, "clause_pred_clause_test: null test result");

src/backend/optimizer/util/clauses.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.72 2000/08/21 17:22:34 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.73 2000/08/24 03:29:05 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1447,7 +1447,6 @@ simplify_op_or_func(Expr *expr, List *args)
 	bool		has_nonconst_input = false;
 	bool		has_null_input = false;
 	bool		const_is_null;
-	bool		isDone;
 
 	/*
 	 * Check for constant inputs and especially constant-NULL inputs.
@@ -1566,8 +1565,7 @@ simplify_op_or_func(Expr *expr, List *args)
 	econtext = MakeExprContext(NULL, CurrentMemoryContext);
 
 	const_val = ExecEvalExprSwitchContext((Node *) newexpr, econtext,
-										  &const_is_null, &isDone);
-	Assert(isDone);				/* if this isn't set, we blew it... */
+										  &const_is_null, NULL);
 
 	/* Must copy result out of sub-context used by expression eval */
 	const_val = datumCopy(const_val, resultTypByVal, resultTypLen);

src/backend/parser/parse_func.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.88 2000/08/20 00:44:18 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.89 2000/08/24 03:29:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -560,13 +560,13 @@ ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 	{							/* we know all of these fields already */
 
 		/*
-		 * We create a funcnode with a placeholder function SetEval.
-		 * SetEval() never actually gets executed.	When the function
-		 * evaluation routines see it, they use the funcid projected out
-		 * from the relation as the actual function to call. Example:
-		 * retrieve (emp.mgr.name) The plan for this will scan the emp
-		 * relation, projecting out the mgr attribute, which is a funcid.
-		 * This function is then called (instead of SetEval) and "name" is
+		 * We create a funcnode with a placeholder function seteval().
+		 * At runtime, seteval() will execute the function identified
+		 * by the funcid it receives as parameter.
+		 *
+		 * Example: retrieve (emp.mgr.name).  The plan for this will scan the
+		 * emp relation, projecting out the mgr attribute, which is a funcid.
+		 * This function is then called (via seteval()) and "name" is
 		 * projected from its result.
 		 */
 		funcid = F_SETEVAL;

src/backend/parser/parse_node.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_node.c,v 1.44 2000/08/08 15:42:04 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_node.c,v 1.45 2000/08/24 03:29:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -34,7 +34,6 @@
 #include "utils/lsyscache.h"
 #include "utils/syscache.h"
 
-static void disallow_setop(char *op, Type optype, Node *operand);
 static bool fitsInFloat(Value *value);
 
 
@@ -71,7 +70,6 @@ make_operand(char *opname,
 
 	if (tree != NULL)
 	{
-		disallow_setop(opname, target_type, tree);
 		/* must coerce? */
 		if (target_typeId != orig_typeId)
 			result = coerce_type(NULL, tree, orig_typeId, target_typeId, -1);
@@ -96,21 +94,6 @@ make_operand(char *opname,
 }	/* make_operand() */
 
 
-static void
-disallow_setop(char *op, Type optype, Node *operand)
-{
-	if (operand == NULL)
-		return;
-
-	if (nodeTag(operand) == T_Iter)
-	{
-		elog(ERROR, "An operand to the '%s' operator returns a set of %s,"
-			 "\n\tbut '%s' takes single values, not sets.",
-			 op, typeTypeName(optype), op);
-	}
-}
-
-
 /* make_op()
  * Operator construction.
  *

src/backend/utils/adt/sets.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/sets.c,v 1.32 2000/06/09 01:11:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/sets.c,v 1.33 2000/08/24 03:29:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,6 +21,8 @@
 #include "catalog/catname.h"
 #include "catalog/indexing.h"
 #include "catalog/pg_proc.h"
+#include "executor/executor.h"
+#include "utils/fcache.h"
 #include "utils/sets.h"
 #include "utils/syscache.h"
 
@@ -30,9 +32,9 @@ extern CommandDest whereToSendOutput;	/* defined in tcop/postgres.c */
 /*
  *	  SetDefine		   - converts query string defining set to an oid
  *
- *	  The query string is used to store the set as a function in
- *	  pg_proc.	The name of the function is then changed to use the
- *	  OID of its tuple in pg_proc.
+ *	  We create an SQL function having the given querystring as its body.
+ *	  The name of the function is then changed to use the OID of its tuple
+ *	  in pg_proc.
  */
 Oid
 SetDefine(char *querystr, char *typename)
@@ -57,11 +59,11 @@ SetDefine(char *querystr, char *typename)
 							 querystr,	/* sourceCode */
 							 fileName,	/* fileName */
 							 true,		/* trusted */
-							 false,		/* canCache XXX appropriate? */
-							 false,		/* isStrict XXX appropriate? */
+							 false,		/* canCache (assume unsafe) */
+							 false,		/* isStrict (irrelevant, no args) */
 							 100,		/* byte_pct */
-							 0, /* perbyte_cpu */
-							 0, /* percall_cpu */
+							 0,			/* perbyte_cpu */
+							 0,			/* percall_cpu */
 							 100,		/* outin_ratio */
 							 NIL,		/* argList */
 							 whereToSendOutput);
@@ -74,11 +76,12 @@ SetDefine(char *querystr, char *typename)
 	 * until you start the next command.)
 	 */
 	CommandCounterIncrement();
+
 	tup = SearchSysCacheTuple(PROCOID,
 							  ObjectIdGetDatum(setoid),
 							  0, 0, 0);
 	if (!HeapTupleIsValid(tup))
-		elog(ERROR, "setin: unable to define set %s", querystr);
+		elog(ERROR, "SetDefine: unable to define set %s", querystr);
 
 	/*
 	 * We can tell whether the set was already defined by checking the
@@ -86,7 +89,7 @@ SetDefine(char *querystr, char *typename)
 	 * oid>" it's already defined.
 	 */
 	proc = (Form_pg_proc) GETSTRUCT(tup);
-	if (!strcmp((char *) procname, (char *) &(proc->proname)))
+	if (strcmp(procname, NameStr(proc->proname)) == 0)
 	{
 		/* make the real proc name */
 		sprintf(realprocname, "set%u", setoid);
@@ -120,7 +123,7 @@ SetDefine(char *querystr, char *typename)
 			setoid = newtup->t_data->t_oid;
 		}
 		else
-			elog(ERROR, "setin: could not find new set oid tuple");
+			elog(ERROR, "SetDefine: could not find new set oid tuple");
 
 		if (RelationGetForm(procrel)->relhasindex)
 		{
@@ -132,20 +135,79 @@ SetDefine(char *querystr, char *typename)
 		}
 		heap_close(procrel, RowExclusiveLock);
 	}
+
 	return setoid;
 }
 
-/* This function is a placeholder.	The parser uses the OID of this
- * function to fill in the :funcid field  of a set.  This routine is
- * never executed.	At runtime, the OID of the actual set is substituted
- * into the :funcid.
+/*
+ * This function executes set evaluation.  The parser sets up a set reference
+ * as a call to this function with the OID of the set to evaluate as argument.
+ *
+ * We build a new fcache for execution of the set's function and run the
+ * function until it says "no mas".  The fn_extra field of the call's
+ * FmgrInfo record is a handy place to hold onto the fcache.  (Since this
+ * is a built-in function, there is no competing use of fn_extra.)
  */
 Datum
 seteval(PG_FUNCTION_ARGS)
 {
 	Oid			funcoid = PG_GETARG_OID(0);
+	FunctionCachePtr fcache;
+	Datum		result;
+	bool		isNull;
+	ExprDoneCond isDone;
+
+	/*
+	 * If this is the first call, we need to set up the fcache for the
+	 * target set's function.
+	 */
+	fcache = (FunctionCachePtr) fcinfo->flinfo->fn_extra;
+	if (fcache == NULL)
+	{
+		fcache = init_fcache(funcoid, 0, fcinfo->flinfo->fn_mcxt);
+		fcinfo->flinfo->fn_extra = (void *) fcache;
+	}
+
+	/*
+	 * Evaluate the function.  NOTE: we need no econtext because there
+	 * are no arguments to evaluate.
+	 */
+
+	/* ExecMakeFunctionResult assumes these are initialized at call: */
+	isNull = false;
+	isDone = ExprSingleResult;
 
-	elog(ERROR, "seteval called for OID %u", funcoid);
+	result = ExecMakeFunctionResult(fcache,
+									NIL,
+									NULL, /* no econtext, see above */
+									&isNull,
+									&isDone);
+
+	/*
+	 * If we're done with the results of this set function, get rid of
+	 * its func cache so that we will start from the top next time.
+	 * (Can you say "memory leak"?  This feature is a crock anyway...)
+	 */
+	if (isDone != ExprMultipleResult)
+	{
+		pfree(fcache);
+		fcinfo->flinfo->fn_extra = NULL;
+	}
+
+	/*
+	 * Return isNull/isDone status.
+	 */
+	fcinfo->isnull = isNull;
+
+	if (isDone != ExprSingleResult)
+	{
+		ReturnSetInfo  *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
+
+		if (rsi && IsA(rsi, ReturnSetInfo))
+			rsi->isDone = isDone;
+		else
+			elog(ERROR, "Set-valued function called in context that cannot accept a set");
+	}
 
-	PG_RETURN_INT32(0);			/* keep compiler happy */
+	PG_RETURN_DATUM(result);
 }

src/backend/utils/cache/fcache.c

 /*-------------------------------------------------------------------------
  *
  * fcache.c
- *	  Code for the 'function cache' used in Oper and Func nodes....
+ *	  Code for the 'function cache' used in Oper and Func nodes.
+ *
  *
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/cache/Attic/fcache.c,v 1.36 2000/08/11 18:35:50 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/cache/Attic/fcache.c,v 1.37 2000/08/24 03:29:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
-#include "access/heapam.h"
-#include "catalog/pg_language.h"
-#include "catalog/pg_proc.h"
-#include "catalog/pg_type.h"
-#include "parser/parsetree.h"
-#include "utils/builtins.h"
-#include "utils/fcache2.h"
-#include "utils/syscache.h"
-
-static Oid	GetDynamicFuncArgType(Var *arg, ExprContext *econtext);
-static FunctionCachePtr init_fcache(Oid foid,
-									List *argList,
-									ExprContext *econtext);
-
-#define FuncArgTypeIsDynamic(arg) \
-	(IsA(arg,Var) && ((Var*)arg)->varattno == InvalidAttrNumber)
-
-static Oid
-GetDynamicFuncArgType(Var *arg, ExprContext *econtext)
-{
-	char	   *relname;
-	int			rtid;
-	HeapTuple	tup;
-
-	Assert(IsA(arg, Var));
+#include "utils/fcache.h"
 
-	rtid = ((Var *) arg)->varno;
-	relname = (char *) getrelname(rtid, econtext->ecxt_range_table);
-
-	tup = SearchSysCacheTuple(TYPENAME,
-							  PointerGetDatum(relname),
-							  0, 0, 0);
-	if (!tup)
-		elog(ERROR, "Lookup failed on type tuple for class %s",
-			 relname);
-
-	return tup->t_data->t_oid;
-}
 
 /*-----------------------------------------------------------------
  *
- * Initialize a 'FunctionCache' struct given the PG_PROC oid.
+ * Build a 'FunctionCache' struct given the PG_PROC oid.
  *
  *-----------------------------------------------------------------
  */
-static FunctionCachePtr
-init_fcache(Oid foid,
-			List *argList,
-			ExprContext *econtext)
+FunctionCachePtr
+init_fcache(Oid foid, int nargs, MemoryContext fcacheCxt)
 {
-	HeapTuple	procedureTuple;
-	HeapTuple	typeTuple;
-	Form_pg_proc procedureStruct;
-	Form_pg_type typeStruct;
+	MemoryContext oldcontext;
 	FunctionCachePtr retval;
-	int			nargs;
-	Datum		tmp;
-	bool		isNull;
+
+	/* Switch to a context long-lived enough for the fcache entry */
+	oldcontext = MemoryContextSwitchTo(fcacheCxt);
 
 	retval = (FunctionCachePtr) palloc(sizeof(FunctionCache));
 	MemSet(retval, 0, sizeof(FunctionCache));
-	retval->fcacheCxt = CurrentMemoryContext;
-
-	/* ----------------
-	 *	 get the procedure tuple corresponding to the given functionOid
-	 *
-	 *	 NB: use SearchSysCacheTupleCopy to ensure tuple lives long enough
-	 * ----------------
-	 */
-	procedureTuple = SearchSysCacheTupleCopy(PROCOID,
-											 ObjectIdGetDatum(foid),
-											 0, 0, 0);
 
-	if (!HeapTupleIsValid(procedureTuple))
-		elog(ERROR, "init_fcache: Cache lookup failed for procedure %u",
-			 foid);
+	/* Set up the primary fmgr lookup information */
+	fmgr_info(foid, &(retval->func));
 
-	procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
+	/* Initialize unvarying fields of per-call info block */
+	retval->fcinfo.flinfo = &(retval->func);
+	retval->fcinfo.nargs = nargs;
 
-	/* ----------------
-	 *	 get the return type from the procedure tuple
-	 * ----------------
-	 */
-	typeTuple = SearchSysCacheTuple(TYPEOID,
-						   ObjectIdGetDatum(procedureStruct->prorettype),
-									0, 0, 0);
+	if (nargs > FUNC_MAX_ARGS)
+		elog(ERROR, "init_fcache: too many arguments");
 
-	if (!HeapTupleIsValid(typeTuple))
-		elog(ERROR, "init_fcache: Cache lookup failed for type %u",
-			 procedureStruct->prorettype);
-
-	typeStruct = (Form_pg_type) GETSTRUCT(typeTuple);
-
-	/* ----------------
-	 *	 get the type length and by-value flag from the type tuple
-	 * ----------------
-	 */
-	retval->typlen = typeStruct->typlen;
-	if (typeStruct->typrelid == InvalidOid)
+	/* If function returns set, prepare a resultinfo node for communication */
+	if (retval->func.fn_retset)
 	{
-		/* The return type is not a relation, so just use byval */
-		retval->typbyval = typeStruct->typbyval;
-		retval->returnsTuple = false;
+		retval->fcinfo.resultinfo = (Node *) &(retval->rsinfo);
+		retval->rsinfo.type = T_ReturnSetInfo;
 	}
-	else
-	{
 
-		/*
-		 * This is a hack.	We assume here that any function returning a
-		 * tuple returns it by reference.  This needs to be fixed, since
-		 * actually the mechanism isn't quite like return-by-reference.
-		 */
-		retval->typbyval = false;
-		retval->returnsTuple = true;
-	}
-	retval->foid = foid;
-	retval->language = procedureStruct->prolang;
-	retval->returnsSet = procedureStruct->proretset;
+	retval->argsValid = false;
 	retval->hasSetArg = false;
-	retval->func_state = (char *) NULL;
-	retval->setArg = (Datum) 0;
-
-	/*
-	 * If we are returning exactly one result then we have to copy tuples
-	 * and by reference results because we have to end the execution
-	 * before we return the results.  When you do this everything
-	 * allocated by the executor (i.e. slots and tuples) is freed.
-	 */
-	if ((retval->language == SQLlanguageId) &&
-		!retval->returnsSet &&
-		!retval->typbyval)
-	{
-		TupleTableSlot *slot;
-
-		slot = makeNode(TupleTableSlot);
-		slot->ttc_shouldFree = true;
-		slot->ttc_descIsNew = true;
-		slot->ttc_tupleDescriptor = (TupleDesc) NULL;
-		slot->ttc_buffer = InvalidBuffer;
-		slot->ttc_whichplan = -1;
-
-		retval->funcSlot = (Pointer) slot;
-	}
-	else
-		retval->funcSlot = (Pointer) NULL;
-
-	nargs = procedureStruct->pronargs;
-	retval->nargs = nargs;
-
-	if (nargs > 0)
-	{
-		Oid		   *argTypes;
-
-		if (retval->language == SQLlanguageId)
-		{
-			int			i;
-			List	   *oneArg;
-
-			retval->argOidVect = (Oid *) palloc(retval->nargs * sizeof(Oid));
-			argTypes = procedureStruct->proargtypes;
-			memmove(retval->argOidVect,
-					argTypes,
-					(retval->nargs) * sizeof(Oid));
 
-			for (i = 0;
-				 argList;
-				 i++, argList = lnext(argList))
-			{
-				oneArg = lfirst(argList);
-				if (FuncArgTypeIsDynamic(oneArg))
-					retval->argOidVect[i] = GetDynamicFuncArgType((Var *) oneArg,
-															   econtext);
-			}
-		}
-		else
-			retval->argOidVect = (Oid *) NULL;
-	}
-	else
-	{
-		retval->argOidVect = (Oid *) NULL;
-	}
-
-	if (procedureStruct->prolang == SQLlanguageId)
-	{
-		tmp = SysCacheGetAttr(PROCOID,
-							  procedureTuple,
-							  Anum_pg_proc_prosrc,
-							  &isNull);
-		if (isNull)
-			elog(ERROR, "init_fcache: null prosrc for procedure %u",
-				 foid);
-		retval->src = DatumGetCString(DirectFunctionCall1(textout, tmp));
-		retval->bin = (char *) NULL;
-	}
-	else
-	{
-		retval->src = (char *) NULL;
-		if (procedureStruct->proistrusted)
-			retval->bin = (char *) NULL;
-		else
-		{
-			tmp = SysCacheGetAttr(PROCOID,
-								  procedureTuple,
-								  Anum_pg_proc_probin,
-								  &isNull);
-			if (isNull)
-				elog(ERROR, "init_fcache: null probin for procedure %u",
-					 foid);
-			retval->bin = DatumGetCString(DirectFunctionCall1(textout, tmp));
-		}
-	}
-
-	if (retval->language != SQLlanguageId)
-	{
-		fmgr_info(foid, &(retval->func));
-		retval->nargs = retval->func.fn_nargs;
-	}
-	else
-		retval->func.fn_addr = (PGFunction) NULL;
-
-	heap_freetuple(procedureTuple);
+	MemoryContextSwitchTo(oldcontext);
 
 	return retval;
 }
-
-void
-setFcache(Node *node, Oid foid, List *argList, ExprContext *econtext)
-{
-	MemoryContext oldcontext;
-	FunctionCachePtr fcache;
-
-	/* Switch to a context long-lived enough for the fcache entry */
-	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
-
-	fcache = init_fcache(foid, argList, econtext);
-
-	if (IsA(node, Oper))
-	{
-		Oper	   *onode = (Oper *) node;
-		onode->op_fcache = fcache;
-	}
-	else if (IsA(node, Func))
-	{
-		Func	   *fnode = (Func *) node;
-		fnode->func_fcache = fcache;
-	}
-	else
-		elog(ERROR, "init_fcache: node must be Oper or Func!");
-
-	MemoryContextSwitchTo(oldcontext);
-}

src/backend/utils/fmgr/fmgr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/fmgr/fmgr.c,v 1.45 2000/07/06 05:48:13 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/fmgr/fmgr.c,v 1.46 2000/08/24 03:29:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,6 +17,7 @@
 
 #include "catalog/pg_language.h"
 #include "catalog/pg_proc.h"
+#include "executor/functions.h"
 #include "utils/builtins.h"
 #include "utils/fmgrtab.h"
 #include "utils/syscache.h"
@@ -44,7 +45,6 @@ typedef char *((*func_ptr) ());
 
 static Datum fmgr_oldstyle(PG_FUNCTION_ARGS);
 static Datum fmgr_untrusted(PG_FUNCTION_ARGS);
-static Datum fmgr_sql(PG_FUNCTION_ARGS);
 
 
 /*
@@ -111,6 +111,7 @@ fmgr_info(Oid functionId, FmgrInfo *finfo)
 
 	finfo->fn_oid = functionId;
 	finfo->fn_extra = NULL;
+	finfo->fn_mcxt = CurrentMemoryContext;
 
 	if ((fbp = fmgr_isbuiltin(functionId)) != NULL)
 	{
@@ -119,6 +120,7 @@ fmgr_info(Oid functionId, FmgrInfo *finfo)
 		 */
 		finfo->fn_nargs = fbp->nargs;
 		finfo->fn_strict = fbp->strict;
+		finfo->fn_retset = false; /* assume no builtins return sets! */
 		if (fbp->oldstyle)
 		{
 			finfo->fn_addr = fmgr_oldstyle;
@@ -142,6 +144,7 @@ fmgr_info(Oid functionId, FmgrInfo *finfo)
 
 	finfo->fn_nargs = procedureStruct->pronargs;
 	finfo->fn_strict = procedureStruct->proisstrict;
+	finfo->fn_retset = procedureStruct->proretset;
 
 	if (!procedureStruct->proistrusted)
 	{
@@ -427,21 +430,6 @@ fmgr_untrusted(PG_FUNCTION_ARGS)
 	return 0;					/* keep compiler happy */
 }
 
-/*
- * Handler for SQL-language functions
- */
-static Datum
-fmgr_sql(PG_FUNCTION_ARGS)
-{
-	/*
-	 * XXX It'd be really nice to support SQL functions anywhere that
-	 * builtins are supported.	What would we have to do?  What pitfalls
-	 * are there?
-	 */
-	elog(ERROR, "SQL-language function not supported in this context");
-	return 0;					/* keep compiler happy */
-}
-
 
 /*-------------------------------------------------------------------------
  *		Support routines for callers of fmgr-compatible functions

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_proc.h,v 1.163 2000/08/23 06:04:44 thomas Exp $
+ * $Id: pg_proc.h,v 1.164 2000/08/24 03:29:08 tgl Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -1266,8 +1266,8 @@ DATA(insert OID = 1036 (  aclremove		   PGUID 12 f t f t 2 f 1034 "1034 1033" 10
 DESCR("remove ACL item");
 DATA(insert OID = 1037 (  aclcontains	   PGUID 12 f t f t 2 f 16 "1034 1033" 100 0 0 100  aclcontains - ));
 DESCR("does ACL contain item?");
-DATA(insert OID = 1038 (  seteval		   PGUID 12 f t f t 1 f 23 "26" 100 0 0 100  seteval - ));
-DESCR("");
+DATA(insert OID = 1038 (  seteval		   PGUID 12 f t f t 1 t 23 "26" 100 0 0 100  seteval - ));
+DESCR("internal function supporting PostQuel-style sets");
 DATA(insert OID = 1044 (  bpcharin		   PGUID 12 f t t t 3 f 1042 "0 26 23" 100 0 0 100 bpcharin - ));
 DESCR("(internal)");
 DATA(insert OID = 1045 (  bpcharout		   PGUID 12 f t t t 1 f 23 "0" 100 0 0 100  bpcharout - ));

src/include/commands/defrem.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: defrem.h,v 1.19 2000/02/18 09:29:49 inoue Exp $
+ * $Id: defrem.h,v 1.20 2000/08/24 03:29:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -44,7 +44,6 @@ extern void CreateFunction(ProcedureStmt *stmt, CommandDest dest);
 extern void DefineOperator(char *name, List *parameters);
 extern void DefineAggregate(char *name, List *parameters);
 extern void DefineType(char *name, List *parameters);
-extern void CreateFunction(ProcedureStmt *stmt, CommandDest dest);
 
 /*
  * prototypes in remove.c

src/include/executor/execFlatten.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execFlatten.h,v 1.11 2000/01/26 05:58:05 momjian Exp $
+ * $Id: execFlatten.h,v 1.12 2000/08/24 03:29:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,11 +15,14 @@
 #define EXECFLATTEN_H
 
 #include "nodes/execnodes.h"
-#include "nodes/relation.h"
+#include "nodes/parsenodes.h"
 
-extern Datum ExecEvalIter(Iter *iterNode, ExprContext *econtext, bool *resultIsNull, bool *iterIsDone);
 
-extern void ExecEvalFjoin(TargetEntry *tlist, ExprContext *econtext, bool *isNullVect, bool *fj_isDone);
+extern Datum ExecEvalIter(Iter *iterNode, ExprContext *econtext,
+						  bool *isNull, ExprDoneCond *isDone);
+
+extern void ExecEvalFjoin(TargetEntry *tlist, ExprContext *econtext,
+						  bool *isNullVect, ExprDoneCond *fj_isDone);
 
 
 #endif	 /* EXECFLATTEN_H */

src/include/executor/executor.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: executor.h,v 1.48 2000/08/21 20:55:29 tgl Exp $
+ * $Id: executor.h,v 1.49 2000/08/24 03:29:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -78,14 +78,20 @@ extern char *GetAttributeByNum(TupleTableSlot *slot, AttrNumber attrno,
 				  bool *isNull);
 extern char *GetAttributeByName(TupleTableSlot *slot, char *attname,
 								bool *isNull);
+extern Datum ExecMakeFunctionResult(FunctionCachePtr fcache,
+									List *arguments,
+									ExprContext *econtext,
+									bool *isNull,
+									ExprDoneCond *isDone);
 extern Datum ExecEvalExpr(Node *expression, ExprContext *econtext,
-						  bool *isNull, bool *isDone);
+						  bool *isNull, ExprDoneCond *isDone);
 extern Datum ExecEvalExprSwitchContext(Node *expression, ExprContext *econtext,
-									   bool *isNull, bool *isDone);
+									   bool *isNull, ExprDoneCond *isDone);
 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 extern int	ExecTargetListLength(List *targetlist);
 extern int	ExecCleanTargetListLength(List *targetlist);
-extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo, bool *isDone);
+extern TupleTableSlot *ExecProject(ProjectionInfo *projInfo,
+								   ExprDoneCond *isDone);
 
 /*
  * prototypes from functions in execScan.c

src/include/executor/functions.h

 /*-------------------------------------------------------------------------
  *
  * functions.h
- *
+ *		Declarations for execution of SQL-language functions.
  *
  *
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: functions.h,v 1.13 2000/08/08 15:42:39 tgl Exp $
+ * $Id: functions.h,v 1.14 2000/08/24 03:29:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef FUNCTIONS_H
 #define FUNCTIONS_H
 
-#include "nodes/parsenodes.h"
-#include "utils/syscache.h"
+#include "fmgr.h"
 
-extern Datum postquel_function(FunctionCallInfo fcinfo,
-							   FunctionCachePtr fcache,
-							   bool *isDone);
+extern Datum fmgr_sql(PG_FUNCTION_ARGS);
 
 #endif	 /* FUNCTIONS_H */

src/include/fmgr.h

@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: fmgr.h,v 1.9 2000/07/29 03:26:47 tgl Exp $
+ * $Id: fmgr.h,v 1.10 2000/08/24 03:29:11 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,7 +41,9 @@ typedef struct
     Oid         fn_oid;     /* OID of function (NOT of handler, if any) */
     short       fn_nargs;   /* 0..FUNC_MAX_ARGS, or -1 if variable arg count */
     bool        fn_strict;  /* function is "strict" (NULL in => NULL out) */
+	bool		fn_retset;	/* function returns a set (over multiple calls) */
     void       *fn_extra;   /* extra space for use by handler */
+	MemoryContext fn_mcxt;	/* memory context to store fn_extra in */
 } FmgrInfo;
 
 /*

src/include/nodes/execnodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execnodes.h,v 1.47 2000/08/22 04:06:22 tgl Exp $
+ * $Id: execnodes.h,v 1.48 2000/08/24 03:29:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -120,6 +120,31 @@ typedef struct ExprContext
 	List	   *ecxt_range_table;
 } ExprContext;
 
+/*
+ * Set-result status returned by ExecEvalExpr()
+ */
+typedef enum
+{
+	ExprSingleResult,			/* expression does not return a set */
+	ExprMultipleResult,			/* this result is an element of a set */
+	ExprEndResult				/* there are no more elements in the set */
+} ExprDoneCond;
+
+/*
+ * When calling a function that might return a set (multiple rows),
+ * a node of this type is passed as fcinfo->resultinfo to allow
+ * return status to be passed back.  A function returning set should
+ * raise an error if no such resultinfo is provided.
+ *
+ * XXX this mechanism is a quick hack and probably needs to be redesigned.
+ */
+typedef struct ReturnSetInfo
+{
+	NodeTag		type;
+	ExprDoneCond isDone;
+} ReturnSetInfo;
+
+
 /* ----------------
  *		ProjectionInfo node information
  *

src/include/nodes/nodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodes.h,v 1.74 2000/08/11 23:46:54 tgl Exp $
+ * $Id: nodes.h,v 1.75 2000/08/24 03:29:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -227,7 +227,9 @@ typedef enum NodeTag
 	 * TAGS FOR FUNCTION-CALL CONTEXT AND RESULTINFO NODES (cf. fmgr.h)
 	 *---------------------
 	 */
-	T_TriggerData = 800			/* in commands/trigger.h */
+	T_TriggerData = 800,		/* in commands/trigger.h */
+	T_ReturnSetInfo				/* in nodes/execnodes.h */
+
 } NodeTag;
 
 /*

src/include/nodes/primnodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: primnodes.h,v 1.46 2000/08/08 15:42:59 tgl Exp $
+ * $Id: primnodes.h,v 1.47 2000/08/24 03:29:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,7 +16,10 @@
 
 #include "access/attnum.h"
 #include "nodes/pg_list.h"
-#include "utils/fcache.h"
+
+/* FunctionCache is declared in utils/fcache.h */
+typedef struct FunctionCache *FunctionCachePtr;
+
 
 /* ----------------------------------------------------------------
  *						node definitions

src/include/utils/builtins.h

@@ -7,13 +7,14 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: builtins.h,v 1.133 2000/08/23 06:04:49 thomas Exp $
+ * $Id: builtins.h,v 1.134 2000/08/24 03:29:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef BUILTINS_H
 #define BUILTINS_H
 
+#include "fmgr.h"
 #include "nodes/relation.h"		/* for amcostestimate parameters */
 #include "storage/itemptr.h"
 #include "utils/numeric.h"

src/include/utils/fcache.h

@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: fcache.h,v 1.13 2000/08/08 15:43:12 tgl Exp $
+ * $Id: fcache.h,v 1.14 2000/08/24 03:29:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,45 +19,50 @@
 #define FCACHE_H
 
 #include "fmgr.h"
+#include "nodes/execnodes.h"
 
+/*
+ * A FunctionCache record is built for all functions regardless of language.
+ *
+ * We store the fmgr lookup info to avoid recomputing it on each call.
+ * We also store a prebuilt FunctionCallInfo struct.  When evaluating a
+ * function-returning-set, fcinfo holds the argument values across calls
+ * so that we need not re-evaluate the arguments for each call.  Even for
+ * non-set functions, fcinfo saves a few cycles per call by allowing us to
+ * avoid redundant setup of its fields.
+ */
 
-typedef struct
+typedef struct FunctionCache
 {
-	FmgrInfo	func;			/* info for fmgr call mechanism */
-	Oid			foid;			/* oid of the function in pg_proc */
-	Oid			language;		/* oid of the language in pg_language */
-	int			typlen;			/* length of the return type */
-	bool		typbyval;		/* true if return type is pass by value */
-
-	bool		returnsTuple;	/* true if return type is a tuple */
-	bool		returnsSet;		/* true if func returns a set (multi rows) */
-
-	bool		hasSetArg;		/* true if func is part of a nested dot
-								 * expr whose argument is func returning a
-								 * set ugh! */
-
-	/* If additional info is added to an existing fcache, be sure to
-	 * allocate it in the fcacheCxt.
+	/*
+	 * Function manager's lookup info for the target function.
 	 */
-	MemoryContext fcacheCxt;	/* context the fcache lives in */
-
-	int			nargs;			/* actual number of arguments */
-	Oid		   *argOidVect;		/* oids of all the argument types */
-
-	char	   *src;			/* source code of the function */
-	char	   *bin;			/* binary object code ?? */
-	char	   *func_state;		/* function_state struct for execution */
-
-	Pointer		funcSlot;		/* if one result we need to copy it before
-								 * we end execution of the function and
-								 * free stuff */
-
-	Datum		setArg;			/* current argument for nested dot
-								 * execution Nested dot expressions mean
-								 * we have funcs whose argument is a set
-								 * of tuples */
+	FmgrInfo	func;
+	/*
+	 * Per-call info for calling the target function.  Unvarying fields
+	 * are set up by init_fcache().  Argument values are filled in as needed.
+	 */
+	FunctionCallInfoData fcinfo;
+	/*
+	 * "Resultinfo" node --- used only if target function returns a set.
+	 */
+	ReturnSetInfo rsinfo;
+	/*
+	 * argsValid is true when we are evaluating a set-valued function and
+	 * we are in the middle of a call series; we want to pass the same
+	 * argument values to the function again (and again, until it returns
+	 * ExprEndResult).
+	 */
+	bool		argsValid;		/* TRUE if fcinfo contains valid arguments */
+	/*
+	 * hasSetArg is true if we found a set-valued argument to the function.
+	 * This causes the function result to be a set as well.
+	 */
+	bool		hasSetArg;		/* some argument returns a set */
 } FunctionCache;
 
-typedef FunctionCache *FunctionCachePtr;
+
+extern FunctionCachePtr init_fcache(Oid foid, int nargs,
+									MemoryContext fcacheCxt);
 
 #endif	 /* FCACHE_H */

src/include/utils/fcache2.h

-/*-------------------------------------------------------------------------
- *
- * fcache2.h
- *
- *
- *
- * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * $Id: fcache2.h,v 1.10 2000/01/26 05:58:38 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#ifndef FCACHE2_H
-#define FCACHE2_H
-
-#include "nodes/execnodes.h"
-
-extern void setFcache(Node *node, Oid foid, List *argList, ExprContext *econtext);
-
-#endif	 /* FCACHE2_H */

src/include/utils/sets.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: sets.h,v 1.7 2000/06/09 01:11:15 tgl Exp $
+ * $Id: sets.h,v 1.8 2000/08/24 03:29:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,10 +17,11 @@
 #include "fmgr.h"
 
 
-/* Temporary name of set, before SetDefine changes it. */
-#define GENERICSETNAME "zyxset"
+/* Temporary name of a set function, before SetDefine changes it. */
+#define GENERICSETNAME "ZYX#Set#ZYX"
 
 extern Oid	SetDefine(char *querystr, char *typename);
+
 extern Datum seteval(PG_FUNCTION_ARGS);
 
 #endif	 /* SETS_H */

src/pl/plpgsql/src/pl_exec.c

@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.27 2000/08/13 02:50:35 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.28 2000/08/24 03:29:15 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -2200,7 +2200,6 @@ exec_eval_simple_expr(PLpgSQL_execstate * estate,
 	int			fno;
 	int			i;
 	bool		isnull;
-	bool		isdone;
 	ExprContext *econtext;
 	ParamListInfo paramLI;
 
@@ -2274,9 +2273,7 @@ exec_eval_simple_expr(PLpgSQL_execstate * estate,
 	 * Initialize things
 	 * ----------
 	 */
-	*isNull = FALSE;
 	*rettype = expr->plan_simple_type;
-	isdone = FALSE;
 
 	/* ----------
 	 * Clear the function cache
@@ -2292,14 +2289,17 @@ exec_eval_simple_expr(PLpgSQL_execstate * estate,
 	retval = ExecEvalExprSwitchContext(expr->plan_simple_expr,
 									   econtext,
 									   isNull,
-									   &isdone);
+									   NULL);
 	SPI_pop();
 
 	/*
 	 * Copy the result out of the expression-evaluation memory context,
 	 * so that we can free the expression context.
 	 */
-	retval = datumCopy(retval, get_typbyval(*rettype), get_typlen(*rettype));
+	if (! *isNull)
+		retval = datumCopy(retval,
+						   get_typbyval(*rettype),
+						   get_typlen(*rettype));
 
 	FreeExprContext(econtext);