Revise executor APIs so that all per-query state structure is built in

a per-query memory context created by CreateExecutorState --- and destroyed
by FreeExecutorState.  This provides a final solution to the longstanding
problem of memory leaked by various ExecEndNode calls.

42 files changed, 801 insertions, 542 deletions

diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index a2180b3466f..cf0c1de7c62 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.146 2002/12/13 19:45:45 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.147 2002/12/15 16:17:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1143,8 +1143,7 @@ index_register(Oid heap,
 	/* predicate will likely be null, but may as well copy it */
 	newind->il_info->ii_Predicate = (List *)
 		copyObject(indexInfo->ii_Predicate);
-	newind->il_info->ii_PredicateState = (List *)
-		ExecInitExpr((Expr *) newind->il_info->ii_Predicate, NULL);
+	newind->il_info->ii_PredicateState = NIL;
 
 	newind->il_next = ILHead;
 	ILHead = newind;
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 4e72fc53f02..5ccb70aee75 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.207 2002/12/13 19:45:47 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.208 2002/12/15 16:17:38 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -41,7 +41,6 @@
 #include "executor/executor.h"
 #include "miscadmin.h"
 #include "optimizer/clauses.h"
-#include "optimizer/planmain.h"
 #include "optimizer/prep.h"
 #include "parser/parse_func.h"
 #include "storage/sinval.h"
@@ -912,7 +911,6 @@ BuildIndexInfo(Form_pg_index indexStruct)
 
 	/*
 	 * If partial index, convert predicate into expression nodetree
-	 * and prepare an execution state nodetree for it
 	 */
 	if (VARSIZE(&indexStruct->indpred) > VARHDRSZ)
 	{
@@ -921,9 +919,7 @@ BuildIndexInfo(Form_pg_index indexStruct)
 		predString = DatumGetCString(DirectFunctionCall1(textout,
 								PointerGetDatum(&indexStruct->indpred)));
 		ii->ii_Predicate = stringToNode(predString);
-		fix_opfuncids((Node *) ii->ii_Predicate);
-		ii->ii_PredicateState = (List *)
-			ExecInitExpr((Expr *) ii->ii_Predicate, NULL);
+		ii->ii_PredicateState = NIL;
 		pfree(predString);
 	}
 	else
@@ -1489,9 +1485,10 @@ IndexBuildHeapScan(Relation heapRelation,
 	Datum		attdata[INDEX_MAX_KEYS];
 	char		nulls[INDEX_MAX_KEYS];
 	double		reltuples;
-	List	   *predicate = indexInfo->ii_PredicateState;
+	List	   *predicate;
 	TupleTable	tupleTable;
 	TupleTableSlot *slot;
+	EState	   *estate;
 	ExprContext *econtext;
 	Snapshot	snapshot;
 	TransactionId OldestXmin;
@@ -1504,27 +1501,41 @@ IndexBuildHeapScan(Relation heapRelation,
 	heapDescriptor = RelationGetDescr(heapRelation);
 
 	/*
+	 * Need an EState for evaluation of functional-index functions
+	 * and partial-index predicates.
+	 */
+	estate = CreateExecutorState();
+	econtext = GetPerTupleExprContext(estate);
+
+	/*
 	 * If this is a predicate (partial) index, we will need to evaluate
 	 * the predicate using ExecQual, which requires the current tuple to
-	 * be in a slot of a TupleTable.  In addition, ExecQual must have an
-	 * ExprContext referring to that slot.	Here, we initialize dummy
-	 * TupleTable and ExprContext objects for this purpose. --Nels, Feb 92
-	 *
-	 * We construct the ExprContext anyway since we need a per-tuple
-	 * temporary memory context for function evaluation -- tgl July 00
+	 * be in a slot of a TupleTable.
 	 */
-	if (predicate != NIL)
+	if (indexInfo->ii_Predicate != NIL)
 	{
 		tupleTable = ExecCreateTupleTable(1);
 		slot = ExecAllocTableSlot(tupleTable);
 		ExecSetSlotDescriptor(slot, heapDescriptor, false);
+
+		/* Arrange for econtext's scan tuple to be the tuple under test */
+		econtext->ecxt_scantuple = slot;
+
+		/*
+		 * Set up execution state for predicate.  Note: we mustn't attempt to
+		 * cache this in the indexInfo, since we're building it in a transient
+		 * EState.
+		 */
+		predicate = (List *)
+			ExecPrepareExpr((Expr *) indexInfo->ii_Predicate,
+							estate);
 	}
 	else
 	{
 		tupleTable = NULL;
 		slot = NULL;
+		predicate = NIL;
 	}
-	econtext = MakeExprContext(slot, TransactionCommandContext);
 
 	/*
 	 * Ok, begin our scan of the base relation.  We use SnapshotAny
@@ -1687,9 +1698,10 @@ IndexBuildHeapScan(Relation heapRelation,
 
 	heap_endscan(scan);
 
-	if (predicate != NIL)
+	if (tupleTable)
 		ExecDropTupleTable(tupleTable, true);
-	FreeExprContext(econtext);
+
+	FreeExecutorState(estate);
 
 	return reltuples;
 }
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 9e8f7a46be4..fd8c6b83a82 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.186 2002/12/13 19:45:48 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.187 2002/12/15 16:17:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -35,7 +35,6 @@
 #include "mb/pg_wchar.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
-#include "optimizer/planmain.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
@@ -803,6 +802,8 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 	slot = ExecAllocTableSlot(tupleTable);
 	ExecSetSlotDescriptor(slot, tupDesc, false);
 
+	econtext = GetPerTupleExprContext(estate);
+
 	/*
 	 * Pick up the required catalog information for each attribute in the
 	 * relation, including the input function, the element type (to pass
@@ -841,8 +842,8 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 
 			if (defexpr != NULL)
 			{
-				fix_opfuncids(defexpr);
-				defexprs[num_defaults] = ExecInitExpr((Expr *) defexpr, NULL);
+				defexprs[num_defaults] = ExecPrepareExpr((Expr *) defexpr,
+														 estate);
 				defmap[num_defaults] = i;
 				num_defaults++;
 			}
@@ -873,8 +874,8 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 			/* check whether any constraints actually found */
 			if (node != (Node *) prm)
 			{
-				fix_opfuncids(node);
-				constraintexprs[i] = ExecInitExpr((Expr *) node, NULL);
+				constraintexprs[i] = ExecPrepareExpr((Expr *) node,
+													 estate);
 				hasConstraints = true;
 			}
 		}
@@ -934,8 +935,6 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 	copy_lineno = 0;
 	fe_eof = false;
 
-	econtext = GetPerTupleExprContext(estate);
-
 	/* Make room for a PARAM_EXEC value for domain constraint checks */
 	if (hasConstraints)
 		econtext->ecxt_param_exec_vals = (ParamExecData *)
@@ -953,9 +952,8 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 		/* Reset the per-tuple exprcontext */
 		ResetPerTupleExprContext(estate);
 
-		/* Switch to and reset per-tuple memory context, too */
+		/* Switch into its memory context */
 		MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
-		MemoryContextReset(CurrentMemoryContext);
 
 		/* Initialize all values for row to NULL */
 		MemSet(values, 0, num_phys_attrs * sizeof(Datum));
@@ -1268,6 +1266,8 @@ CopyFrom(Relation rel, List *attnumlist, bool binary, bool oids,
 	ExecDropTupleTable(tupleTable, true);
 
 	ExecCloseIndices(resultRelInfo);
+
+	FreeExecutorState(estate);
 }
 
 
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 05815a2201b..3820dd8b462 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -5,7 +5,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994-5, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.98 2002/12/14 00:17:50 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/explain.c,v 1.99 2002/12/15 16:17:38 tgl Exp $
  *
  */
 
@@ -206,6 +206,8 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, TupOutputState *tstate)
 	gettimeofday(&starttime, NULL);
 
 	ExecutorEnd(queryDesc);
+	FreeQueryDesc(queryDesc);
+
 	CommandCounterIncrement();
 
 	totaltime += elapsed_time(&starttime);
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 7b66eea0b0b..d46b7a389a3 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.94 2002/12/13 19:45:50 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.95 2002/12/15 16:17:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,7 +27,6 @@
 #include "executor/executor.h"
 #include "miscadmin.h"
 #include "optimizer/clauses.h"
-#include "optimizer/planmain.h"
 #include "optimizer/prep.h"
 #include "parser/parsetree.h"
 #include "parser/parse_coerce.h"
@@ -163,7 +162,6 @@ DefineIndex(RangeVar *heapRelation,
 	if (predicate)
 	{
 		cnfPred = canonicalize_qual((Expr *) copyObject(predicate), true);
-		fix_opfuncids((Node *) cnfPred);
 		CheckPredicate(cnfPred, rangetable, relationId);
 	}
 
@@ -173,8 +171,7 @@ DefineIndex(RangeVar *heapRelation,
 	 */
 	indexInfo = makeNode(IndexInfo);
 	indexInfo->ii_Predicate = cnfPred;
-	indexInfo->ii_PredicateState = (List *)
-		ExecInitExpr((Expr *) cnfPred, NULL);
+	indexInfo->ii_PredicateState = NIL;
 	indexInfo->ii_FuncOid = InvalidOid;
 	indexInfo->ii_Unique = unique;
 
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c
index c8607fcf324..b1799e49f8c 100644
--- a/src/backend/commands/portalcmds.c
+++ b/src/backend/commands/portalcmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/portalcmds.c,v 1.5 2002/12/05 15:50:30 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/portalcmds.c,v 1.6 2002/12/15 16:17:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,8 +31,6 @@
 void
 PortalCleanup(Portal portal)
 {
-	MemoryContext oldcontext;
-
 	/*
 	 * sanity checks
 	 */
@@ -40,19 +38,15 @@ PortalCleanup(Portal portal)
 	AssertArg(portal->cleanup == PortalCleanup);
 
 	/*
-	 * set proper portal-executor context before calling ExecMain.
-	 */
-	oldcontext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
-
-	/*
 	 * tell the executor to shutdown the query
 	 */
 	ExecutorEnd(PortalGetQueryDesc(portal));
 
 	/*
-	 * switch back to previous context
+	 * This should be unnecessary since the querydesc should be in the
+	 * portal's memory context, but do it anyway for symmetry.
 	 */
-	MemoryContextSwitchTo(oldcontext);
+	FreeQueryDesc(PortalGetQueryDesc(portal));
 }
 
 
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 98894372fa7..ece9802dc41 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -6,7 +6,7 @@
  * Copyright (c) 2002, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/prepare.c,v 1.10 2002/12/13 19:45:51 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/prepare.c,v 1.11 2002/12/15 16:17:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,7 +15,6 @@
 #include "commands/prepare.h"
 #include "executor/executor.h"
 #include "utils/guc.h"
-#include "optimizer/planmain.h"
 #include "optimizer/planner.h"
 #include "rewrite/rewriteHandler.h"
 #include "tcop/pquery.h"
@@ -50,7 +49,6 @@ static void InitQueryHashTable(void);
 static void StoreQuery(const char *stmt_name, List *query_list,
 		   List *plan_list, List *argtype_list);
 static QueryHashEntry *FetchQuery(const char *plan_name);
-static void RunQuery(QueryDesc *qdesc);
 
 
 /*
@@ -96,33 +94,37 @@ ExecuteQuery(ExecuteStmt *stmt, CommandDest outputDest)
 			   *query_list,
 			   *plan_list;
 	ParamListInfo paramLI = NULL;
+	EState	   *estate;
 
 	/* Look it up in the hash table */
 	entry = FetchQuery(stmt->name);
 
-	/* Make working copies the executor can safely scribble on */
-	query_list = (List *) copyObject(entry->query_list);
-	plan_list = (List *) copyObject(entry->plan_list);
+	query_list = entry->query_list;
+	plan_list = entry->plan_list;
 
 	Assert(length(query_list) == length(plan_list));
 
+	/*
+	 * Need an EState to evaluate parameters; must not delete it till end
+	 * of query, in case parameters are pass-by-reference.
+	 */
+	estate = CreateExecutorState();
+
 	/* Evaluate parameters, if any */
 	if (entry->argtype_list != NIL)
 	{
 		int			nargs = length(entry->argtype_list);
 		int			i = 0;
 		List	   *exprstates;
-		ExprContext *econtext = MakeExprContext(NULL, CurrentMemoryContext);
 
 		/* Parser should have caught this error, but check */
 		if (nargs != length(stmt->params))
 			elog(ERROR, "ExecuteQuery: wrong number of arguments");
 
-		fix_opfuncids((Node *) stmt->params);
-
-		exprstates = (List *) ExecInitExpr((Expr *) stmt->params, NULL);
+		exprstates = (List *) ExecPrepareExpr((Expr *) stmt->params, estate);
 
-		paramLI = (ParamListInfo) palloc0((nargs + 1) * sizeof(ParamListInfoData));
+		paramLI = (ParamListInfo)
+			palloc0((nargs + 1) * sizeof(ParamListInfoData));
 
 		foreach(l, exprstates)
 		{
@@ -130,7 +132,7 @@ ExecuteQuery(ExecuteStmt *stmt, CommandDest outputDest)
 			bool		isNull;
 
 			paramLI[i].value = ExecEvalExprSwitchContext(n,
-														 econtext,
+											 GetPerTupleExprContext(estate),
 														 &isNull,
 														 NULL);
 			paramLI[i].kind = PARAM_NUM;
@@ -173,7 +175,13 @@ ExecuteQuery(ExecuteStmt *stmt, CommandDest outputDest)
 				qdesc->dest = None;
 			}
 
-			RunQuery(qdesc);
+			ExecutorStart(qdesc);
+
+			ExecutorRun(qdesc, ForwardScanDirection, 0L);
+
+			ExecutorEnd(qdesc);
+
+			FreeQueryDesc(qdesc);
 
 			if (log_executor_stats)
 				ShowUsage("EXECUTOR STATISTICS");
@@ -188,7 +196,9 @@ ExecuteQuery(ExecuteStmt *stmt, CommandDest outputDest)
 			CommandCounterIncrement();
 	}
 
-	/* No need to pfree memory, MemoryContext will be reset */
+	FreeExecutorState(estate);
+
+	/* No need to pfree other memory, MemoryContext will be reset */
 }
 
 /*
@@ -334,17 +344,6 @@ FetchQueryParams(const char *plan_name)
 }
 
 /*
- * Actually execute a prepared query.
- */
-static void
-RunQuery(QueryDesc *qdesc)
-{
-	ExecutorStart(qdesc);
-	ExecutorRun(qdesc, ForwardScanDirection, 0L);
-	ExecutorEnd(qdesc);
-}
-
-/*
  * Implements the 'DEALLOCATE' utility statement: deletes the
  * specified plan from storage.
  *
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a7a19c6f741..09c60bdf3f9 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.60 2002/12/13 19:45:51 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.61 2002/12/15 16:17:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -37,7 +37,6 @@
 #include "nodes/makefuncs.h"
 #include "optimizer/clauses.h"
 #include "optimizer/plancat.h"
-#include "optimizer/planmain.h"
 #include "optimizer/prep.h"
 #include "parser/gramparse.h"
 #include "parser/parse_coerce.h"
@@ -2713,6 +2712,7 @@ AlterTableAddCheckConstraint(Relation rel, Constraint *constr)
 	ParseState *pstate;
 	bool		successful = true;
 	HeapScanDesc scan;
+	EState	   *estate;
 	ExprContext *econtext;
 	TupleTableSlot *slot;
 	HeapTuple	tuple;
@@ -2723,9 +2723,7 @@ AlterTableAddCheckConstraint(Relation rel, Constraint *constr)
 
 	/*
 	 * We need to make a parse state and range
-	 * table to allow us to transformExpr and
-	 * fix_opfuncids to get a version of the
-	 * expression we can pass to ExecQual
+	 * table to allow us to do transformExpr()
 	 */
 	pstate = make_parsestate(NULL);
 	rte = addRangeTableEntryForRelation(pstate,
@@ -2765,19 +2763,22 @@ AlterTableAddCheckConstraint(Relation rel, Constraint *constr)
 	 */
 	expr = eval_const_expressions(expr);
 
-	/* And fix the opfuncids */
-	fix_opfuncids(expr);
+	/* Needs to be in implicit-ANDs form for ExecQual */
+	qual = make_ands_implicit((Expr *) expr);
 
-	qual = makeList1(expr);
+	/* Need an EState to run ExecQual */
+	estate = CreateExecutorState();
+	econtext = GetPerTupleExprContext(estate);
 
 	/* build execution state for qual */
-	qualstate = (List *) ExecInitExpr((Expr *) qual, NULL);
+	qualstate = (List *) ExecPrepareExpr((Expr *) qual, estate);
 
 	/* Make tuple slot to hold tuples */
 	slot = MakeTupleTableSlot();
 	ExecSetSlotDescriptor(slot, RelationGetDescr(rel), false);
-	/* Make an expression context for ExecQual */
-	econtext = MakeExprContext(slot, CurrentMemoryContext);
+
+	/* Arrange for econtext's scan tuple to be the tuple under test */
+	econtext->ecxt_scantuple = slot;
 
 	/*
 	 * Scan through the rows now, checking the expression at each row.
@@ -2797,8 +2798,8 @@ AlterTableAddCheckConstraint(Relation rel, Constraint *constr)
 
 	heap_endscan(scan);
 
-	FreeExprContext(econtext);
 	pfree(slot);
+	FreeExecutorState(estate);
 
 	if (!successful)
 		elog(ERROR, "AlterTableAddConstraint: rejected due to CHECK constraint %s",
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index fc0030fe762..c088aaac991 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/typecmds.c,v 1.24 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/typecmds.c,v 1.25 2002/12/15 16:17:43 tgl Exp $
  *
  * DESCRIPTION
  *	  The "DefineFoo" routines take the parse tree and pick out the
@@ -47,7 +47,6 @@
 #include "miscadmin.h"
 #include "nodes/nodes.h"
 #include "optimizer/clauses.h"
-#include "optimizer/planmain.h"
 #include "optimizer/var.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_expr.h"
@@ -1242,6 +1241,7 @@ AlterDomainAddConstraint(List *names, Node *newConstraint)
 	List   *rels;
 	List   *rt;
 	Form_pg_type	typTup;
+	EState *estate;
 	ExprContext *econtext;
 	char   *ccbin;
 	Expr   *expr;
@@ -1338,11 +1338,13 @@ AlterDomainAddConstraint(List *names, Node *newConstraint)
 	 * the constraint is being added to.
 	 */
 	expr = (Expr *) stringToNode(ccbin);
-	fix_opfuncids((Node *) expr);
-	exprstate = ExecInitExpr(expr, NULL);
 
-	/* Make an expression context for ExecEvalExpr */
-	econtext = MakeExprContext(NULL, CurrentMemoryContext);
+	/* Need an EState to run ExecEvalExpr */
+	estate = CreateExecutorState();
+	econtext = GetPerTupleExprContext(estate);
+
+	/* build execution state for expr */
+	exprstate = ExecPrepareExpr(expr, estate);
 
 	rels = get_rels_with_domain(domainoid);
 
@@ -1377,7 +1379,9 @@ AlterDomainAddConstraint(List *names, Node *newConstraint)
 				econtext->domainValue_datum = d;
 				econtext->domainValue_isNull = isNull;
 
-				conResult = ExecEvalExpr(exprstate, econtext, &isNull, NULL);
+				conResult = ExecEvalExprSwitchContext(exprstate,
+													  econtext,
+													  &isNull, NULL);
 
 				if (!isNull && !DatumGetBool(conResult))
 					elog(ERROR, "AlterDomainAddConstraint: Domain %s constraint %s failed",
@@ -1393,7 +1397,7 @@ AlterDomainAddConstraint(List *names, Node *newConstraint)
 		heap_close(testrel, NoLock);
 	}
 
-	FreeExprContext(econtext);
+	FreeExecutorState(estate);
 
 	/* Clean up */
 	heap_close(rel, NoLock);
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 51082689250..48870b4bca1 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.244 2002/10/31 19:25:29 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.245 2002/12/15 16:17:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1437,6 +1437,8 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 	 * We need a ResultRelInfo and an EState so we can use the regular
 	 * executor's index-entry-making machinery.
 	 */
+	estate = CreateExecutorState();
+
 	resultRelInfo = makeNode(ResultRelInfo);
 	resultRelInfo->ri_RangeTableIndex = 1;		/* dummy */
 	resultRelInfo->ri_RelationDesc = onerel;
@@ -1444,7 +1446,6 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 
 	ExecOpenIndices(resultRelInfo);
 
-	estate = CreateExecutorState();
 	estate->es_result_relations = resultRelInfo;
 	estate->es_num_result_relations = 1;
 	estate->es_result_relation_info = resultRelInfo;
@@ -2484,6 +2485,8 @@ repair_frag(VRelStats *vacrelstats, Relation onerel,
 	ExecDropTupleTable(tupleTable, true);
 
 	ExecCloseIndices(resultRelInfo);
+
+	FreeExecutorState(estate);
 }
 
 /*
diff --git a/src/backend/executor/README b/src/backend/executor/README
index d9b0ea1275a..ebdbe2d9d0c 100644
--- a/src/backend/executor/README
+++ b/src/backend/executor/README
@@ -1,4 +1,4 @@
-$Header: /cvsroot/pgsql/src/backend/executor/README,v 1.2 2002/12/05 15:50:30 tgl Exp $
+$Header: /cvsroot/pgsql/src/backend/executor/README,v 1.3 2002/12/15 16:17:45 tgl Exp $
 
 The Postgres Executor
 ---------------------
@@ -60,6 +60,83 @@ ExprState nodes.  (Actually, there are also List nodes, which are used as
 "glue" in all four kinds of tree.)
 
 
+Memory Management
+-----------------
+
+A "per query" memory context is created during CreateExecutorState();
+all storage allocated during an executor invocation is allocated in that
+context or a child context.  This allows easy reclamation of storage
+during executor shutdown --- rather than messing with retail pfree's and
+probable storage leaks, we just destroy the memory context.
+
+In particular, the plan state trees and expression state trees described
+in the previous section are allocated in the per-query memory context.
+
+To avoid intra-query memory leaks, most processing while a query runs
+is done in "per tuple" memory contexts, which are so-called because they
+are typically reset to empty once per tuple.  Per-tuple contexts are usually
+associated with ExprContexts, and commonly each PlanState node has its own
+ExprContext to evaluate its qual and targetlist expressions in.
+
+
+Query Processing Control Flow
+-----------------------------
+
+This is a sketch of control flow for full query processing:
+
+	CreateQueryDesc
+
+	ExecutorStart
+		CreateExecutorState
+			creates per-query context
+		switch to per-query context to run ExecInitNode
+		ExecInitNode --- recursively scans plan tree
+			CreateExprContext
+				creates per-tuple context
+			ExecInitExpr
+
+	ExecutorRun
+		ExecProcNode --- recursively called in per-query context
+			ExecEvalExpr --- called in per-tuple context
+			ResetExprContext --- to free memory
+
+	ExecutorEnd
+		ExecEndNode --- recursively releases resources
+		FreeExecutorState
+			frees per-query context and child contexts
+
+	FreeQueryDesc
+
+Per above comments, it's not really critical for ExecEndNode to free any
+memory; it'll all go away in FreeExecutorState anyway.  However, we do need to
+be careful to close relations, drop buffer pins, etc, so we do need to scan
+the plan state tree to find these sorts of resources.
+
+
+The executor can also be used to evaluate simple expressions without any Plan
+tree ("simple" meaning "no aggregates and no sub-selects", though such might
+be hidden inside function calls).  This case has a flow of control like
+
+	CreateExecutorState
+		creates per-query context
+
+	CreateExprContext	-- or use GetPerTupleExprContext(estate)
+		creates per-tuple context
+
+	ExecPrepareExpr
+		switch to per-query context to run ExecInitExpr
+		ExecInitExpr
+
+	Repeatedly do:
+		ExecEvalExprSwitchContext
+			ExecEvalExpr --- called in per-tuple context
+		ResetExprContext --- to free memory
+
+	FreeExecutorState
+		frees per-query context, as well as ExprContext
+		(a separate FreeExprContext call is not necessary)
+
+
 EvalPlanQual (READ COMMITTED update checking)
 ---------------------------------------------
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index bac7398825e..a25f2f2e296 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.192 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.193 2002/12/15 16:17:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,7 +40,6 @@
 #include "executor/execdebug.h"
 #include "executor/execdefs.h"
 #include "miscadmin.h"
-#include "optimizer/planmain.h"
 #include "optimizer/var.h"
 #include "parser/parsetree.h"
 #include "utils/acl.h"
@@ -53,7 +52,6 @@ static void initResultRelInfo(ResultRelInfo *resultRelInfo,
 				  Index resultRelationIndex,
 				  List *rangeTable,
 				  CmdType operation);
-static void EndPlan(PlanState *planstate, EState *estate);
 static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate,
 			CmdType operation,
 			long numberTuples,
@@ -86,27 +84,31 @@ static void ExecCheckRTEPerms(RangeTblEntry *rte, CmdType operation);
  * field of the QueryDesc is filled in to describe the tuples that will be
  * returned, and the internal fields (estate and planstate) are set up.
  *
- * XXX this will change soon:
- * NB: the CurrentMemoryContext when this is called must be the context
- * to be used as the per-query context for the query plan.	ExecutorRun()
- * and ExecutorEnd() must be called in this same memory context.
+ * NB: the CurrentMemoryContext when this is called will become the parent
+ * of the per-query context used for this Executor invocation.
  * ----------------------------------------------------------------
  */
 void
 ExecutorStart(QueryDesc *queryDesc)
 {
 	EState	   *estate;
+	MemoryContext oldcontext;
 
 	/* sanity checks: queryDesc must not be started already */
 	Assert(queryDesc != NULL);
 	Assert(queryDesc->estate == NULL);
 
 	/*
-	 * Build EState, fill with parameters from queryDesc
+	 * Build EState, switch into per-query memory context for startup.
 	 */
 	estate = CreateExecutorState();
 	queryDesc->estate = estate;
 
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	/*
+	 * Fill in parameters, if any, from queryDesc
+	 */
 	estate->es_param_list_info = queryDesc->params;
 
 	if (queryDesc->plantree->nParamExec > 0)
@@ -128,6 +130,8 @@ ExecutorStart(QueryDesc *queryDesc)
 	 * Initialize the plan state tree
 	 */
 	InitPlan(queryDesc);
+
+	MemoryContextSwitchTo(oldcontext);
 }
 
 /* ----------------------------------------------------------------
@@ -152,23 +156,30 @@ TupleTableSlot *
 ExecutorRun(QueryDesc *queryDesc,
 			ScanDirection direction, long count)
 {
-	CmdType		operation;
 	EState	   *estate;
+	CmdType		operation;
 	CommandDest dest;
 	DestReceiver *destfunc;
 	TupleTableSlot *result;
+	MemoryContext oldcontext;
+
+	/* sanity checks */
+	Assert(queryDesc != NULL);
+
+	estate = queryDesc->estate;
+
+	Assert(estate != NULL);
 
 	/*
-	 * sanity checks
+	 * Switch into per-query memory context
 	 */
-	Assert(queryDesc != NULL);
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
 
 	/*
 	 * extract information from the query descriptor and the query
 	 * feature.
 	 */
 	operation = queryDesc->operation;
-	estate = queryDesc->estate;
 	dest = queryDesc->dest;
 
 	/*
@@ -199,6 +210,8 @@ ExecutorRun(QueryDesc *queryDesc,
 	 */
 	(*destfunc->cleanup) (destfunc);
 
+	MemoryContextSwitchTo(oldcontext);
+
 	return result;
 }
 
@@ -213,72 +226,37 @@ void
 ExecutorEnd(QueryDesc *queryDesc)
 {
 	EState	   *estate;
+	MemoryContext oldcontext;
 
 	/* sanity checks */
 	Assert(queryDesc != NULL);
 
 	estate = queryDesc->estate;
 
-	EndPlan(queryDesc->planstate, estate);
-
-	if (estate->es_snapshot != NULL)
-	{
-		if (estate->es_snapshot->xcnt > 0)
-			pfree(estate->es_snapshot->xip);
-		pfree(estate->es_snapshot);
-		estate->es_snapshot = NULL;
-	}
-
-	if (estate->es_param_exec_vals != NULL)
-	{
-		pfree(estate->es_param_exec_vals);
-		estate->es_param_exec_vals = NULL;
-	}
-}
-
-
-/*
- * CreateExecutorState
- */
-EState *
-CreateExecutorState(void)
-{
-	EState	   *state;
+	Assert(estate != NULL);
 
 	/*
-	 * create a new executor state
+	 * Switch into per-query memory context to run ExecEndPlan
 	 */
-	state = makeNode(EState);
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	ExecEndPlan(queryDesc->planstate, estate);
 
 	/*
-	 * initialize the Executor State structure
+	 * Must switch out of context before destroying it
 	 */
-	state->es_direction = ForwardScanDirection;
-	state->es_range_table = NIL;
-
-	state->es_result_relations = NULL;
-	state->es_num_result_relations = 0;
-	state->es_result_relation_info = NULL;
-
-	state->es_junkFilter = NULL;
-
-	state->es_into_relation_descriptor = NULL;
-
-	state->es_param_list_info = NULL;
-	state->es_param_exec_vals = NULL;
-
-	state->es_tupleTable = NULL;
-
-	state->es_query_cxt = CurrentMemoryContext;
-
-	state->es_instrument = false;
-
-	state->es_per_tuple_exprcontext = NULL;
+	MemoryContextSwitchTo(oldcontext);
 
 	/*
-	 * return the executor state structure
+	 * Release EState and per-query memory context.  This should release
+	 * everything the executor has allocated.
 	 */
-	return state;
+	FreeExecutorState(estate);
+
+	/* Reset queryDesc fields that no longer point to anything */
+	queryDesc->tupDesc = NULL;
+	queryDesc->estate = NULL;
+	queryDesc->planstate = NULL;
 }
 
 
@@ -794,13 +772,13 @@ initResultRelInfo(ResultRelInfo *resultRelInfo,
 }
 
 /* ----------------------------------------------------------------
- *		EndPlan
+ *		ExecEndPlan
  *
  *		Cleans up the query plan -- closes files and frees up storage
  * ----------------------------------------------------------------
  */
-static void
-EndPlan(PlanState *planstate, EState *estate)
+void
+ExecEndPlan(PlanState *planstate, EState *estate)
 {
 	ResultRelInfo *resultRelInfo;
 	int			i;
@@ -1542,9 +1520,8 @@ ExecRelCheck(ResultRelInfo *resultRelInfo,
 		for (i = 0; i < ncheck; i++)
 		{
 			qual = (List *) stringToNode(check[i].ccbin);
-			fix_opfuncids((Node *) qual);
 			resultRelInfo->ri_ConstraintExprs[i] = (List *)
-				ExecInitExpr((Expr *) qual, NULL);
+				ExecPrepareExpr((Expr *) qual, estate);
 		}
 		MemoryContextSwitchTo(oldContext);
 	}
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c
index a3f79c3ac80..971773b1212 100644
--- a/src/backend/executor/execQual.c
+++ b/src/backend/executor/execQual.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.120 2002/12/14 00:17:50 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.121 2002/12/15 16:17:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,6 +40,7 @@
 #include "executor/functions.h"
 #include "executor/nodeSubplan.h"
 #include "miscadmin.h"
+#include "optimizer/planmain.h"
 #include "parser/parse_expr.h"
 #include "utils/acl.h"
 #include "utils/array.h"
@@ -1896,9 +1897,11 @@ ExecEvalExprSwitchContext(ExprState *expression,
  * cleanup work can register a shutdown callback in the ExprContext.
  *
  *	'node' is the root of the expression tree to examine
- *	'parent' is the PlanState node that owns the expression,
- *		or NULL if we are preparing an expression that is not associated
- *		with a plan.  (If so, it can't have aggs or subplans.)
+ *	'parent' is the PlanState node that owns the expression.
+ *
+ * 'parent' may be NULL if we are preparing an expression that is not
+ * associated with a plan tree.  (If so, it can't have aggs or subplans.)
+ * This case should usually come through ExecPrepareExpr, not directly here.
  */
 ExprState *
 ExecInitExpr(Expr *node, PlanState *parent)
@@ -2017,6 +2020,7 @@ ExecInitExpr(Expr *node, PlanState *parent)
 				 * parent->subPlan.  The subplans will be initialized later.
 				 */
 				parent->subPlan = lcons(sstate, parent->subPlan);
+				sstate->sub_estate = NULL;
 				sstate->planstate = NULL;
 
 				sstate->oper = (List *)
@@ -2149,6 +2153,7 @@ ExecInitExprInitPlan(SubPlan *node, PlanState *parent)
 		elog(ERROR, "ExecInitExpr: SubPlan not expected here");
 
 	/* The subplan's state will be initialized later */
+	sstate->sub_estate = NULL;
 	sstate->planstate = NULL;
 
 	sstate->oper = (List *) ExecInitExpr((Expr *) node->oper, parent);
@@ -2159,6 +2164,33 @@ ExecInitExprInitPlan(SubPlan *node, PlanState *parent)
 	return sstate;
 }
 
+/*
+ * ExecPrepareExpr --- initialize for expression execution outside a normal
+ * Plan tree context.
+ *
+ * This differs from ExecInitExpr in that we don't assume the caller is
+ * already running in the EState's per-query context.  Also, we apply
+ * fix_opfuncids() to the passed expression tree to be sure it is ready
+ * to run.  (In ordinary Plan trees the planner will have fixed opfuncids,
+ * but callers outside the executor will not have done this.)
+ */
+ExprState *
+ExecPrepareExpr(Expr *node, EState *estate)
+{
+	ExprState  *result;
+	MemoryContext oldcontext;
+
+	fix_opfuncids((Node *) node);
+
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	result = ExecInitExpr(node, NULL);
+
+	MemoryContextSwitchTo(oldcontext);
+
+	return result;
+}
+
 
 /* ----------------------------------------------------------------
  *					 ExecQual / ExecTargetList / ExecProject
diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index 36997a49103..6c2cece7b6e 100644
--- a/src/backend/executor/execUtils.c
+++ b/src/backend/executor/execUtils.c
@@ -8,13 +8,20 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.92 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.93 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 /*
  * INTERFACE ROUTINES
+ *		CreateExecutorState		Create/delete executor working state
+ *		FreeExecutorState
+ *		CreateExprContext
+ *		FreeExprContext
+ *
  *		ExecAssignExprContext	Common code for plan node init routines.
+ *		ExecAssignResultType
+ *		etc
  *
  *		ExecOpenIndices			\
  *		ExecCloseIndices		 | referenced by InitPlan, EndPlan,
@@ -26,7 +33,6 @@
  *	 NOTES
  *		This file has traditionally been the place to stick misc.
  *		executor support stuff that doesn't really go anyplace else.
- *
  */
 
 #include "postgres.h"
@@ -64,6 +70,7 @@ extern int	NIndexTupleProcessed;		/* have to be defined in the
 
 static void ShutdownExprContext(ExprContext *econtext);
 
+
 /* ----------------------------------------------------------------
  *						statistic functions
  * ----------------------------------------------------------------
@@ -124,137 +131,264 @@ DisplayTupleCount(FILE *statfp)
 }
 #endif
 
+
 /* ----------------------------------------------------------------
- *				 miscellaneous node-init support functions
+ *				 Executor state and memory management functions
  * ----------------------------------------------------------------
  */
 
 /* ----------------
- *		ExecAssignExprContext
+ *		CreateExecutorState
  *
- *		This initializes the ExprContext field.  It is only necessary
- *		to do this for nodes which use ExecQual or ExecProject
- *		because those routines depend on econtext.	Other nodes that
- *		don't have to evaluate expressions don't need to do this.
+ *		Create and initialize an EState node, which is the root of
+ *		working storage for an entire Executor invocation.
  *
- * Note: we assume CurrentMemoryContext is the correct per-query context.
- * This should be true during plan node initialization.
+ * Principally, this creates the per-query memory context that will be
+ * used to hold all working data that lives till the end of the query.
+ * Note that the per-query context will become a child of the caller's
+ * CurrentMemoryContext.
  * ----------------
  */
-void
-ExecAssignExprContext(EState *estate, PlanState *planstate)
+EState *
+CreateExecutorState(void)
 {
-	ExprContext *econtext = makeNode(ExprContext);
+	EState	   *estate;
+	MemoryContext qcontext;
+	MemoryContext oldcontext;
 
-	econtext->ecxt_scantuple = NULL;
-	econtext->ecxt_innertuple = NULL;
-	econtext->ecxt_outertuple = NULL;
-	econtext->ecxt_per_query_memory = CurrentMemoryContext;
+	/*
+	 * Create the per-query context for this Executor run.
+	 */
+	qcontext = AllocSetContextCreate(CurrentMemoryContext,
+									 "ExecutorState",
+									 ALLOCSET_DEFAULT_MINSIZE,
+									 ALLOCSET_DEFAULT_INITSIZE,
+									 ALLOCSET_DEFAULT_MAXSIZE);
 
 	/*
-	 * Create working memory for expression evaluation in this context.
+	 * Make the EState node within the per-query context.  This way,
+	 * we don't need a separate pfree() operation for it at shutdown.
 	 */
-	econtext->ecxt_per_tuple_memory =
-		AllocSetContextCreate(CurrentMemoryContext,
-							  "PlanExprContext",
-							  ALLOCSET_DEFAULT_MINSIZE,
-							  ALLOCSET_DEFAULT_INITSIZE,
-							  ALLOCSET_DEFAULT_MAXSIZE);
-	econtext->ecxt_param_exec_vals = estate->es_param_exec_vals;
-	econtext->ecxt_param_list_info = estate->es_param_list_info;
-	econtext->ecxt_aggvalues = NULL;
-	econtext->ecxt_aggnulls = NULL;
-	econtext->ecxt_callbacks = NULL;
+	oldcontext = MemoryContextSwitchTo(qcontext);
+
+	estate = makeNode(EState);
+
+	/*
+	 * Initialize all fields of the Executor State structure
+	 */
+	estate->es_direction = ForwardScanDirection;
+	estate->es_snapshot = SnapshotNow;
+	estate->es_range_table = NIL;
+
+	estate->es_result_relations = NULL;
+	estate->es_num_result_relations = 0;
+	estate->es_result_relation_info = NULL;
+
+	estate->es_junkFilter = NULL;
+	estate->es_into_relation_descriptor = NULL;
+
+	estate->es_param_list_info = NULL;
+	estate->es_param_exec_vals = NULL;
+
+	estate->es_query_cxt = qcontext;
+
+	estate->es_tupleTable = NULL;
 
-	planstate->ps_ExprContext = econtext;
+	estate->es_processed = 0;
+	estate->es_lastoid = InvalidOid;
+	estate->es_rowMark = NIL;
+
+	estate->es_instrument = false;
+
+	estate->es_exprcontexts = NIL;
+
+	estate->es_per_tuple_exprcontext = NULL;
+
+	estate->es_origPlan = NULL;
+	estate->es_evalPlanQual = NULL;
+	estate->es_evTupleNull = NULL;
+	estate->es_evTuple = NULL;
+	estate->es_useEvalPlan = false;
+
+	/*
+	 * Return the executor state structure
+	 */
+	MemoryContextSwitchTo(oldcontext);
+
+	return estate;
+}
+
+/* ----------------
+ *		FreeExecutorState
+ *
+ *		Release an EState along with all remaining working storage.
+ *
+ * Note: this is not responsible for releasing non-memory resources,
+ * such as open relations or buffer pins.  But it will shut down any
+ * still-active ExprContexts within the EState.  That is sufficient
+ * cleanup for situations where the EState has only been used for expression
+ * evaluation, and not to run a complete Plan.
+ *
+ * This can be called in any memory context ... so long as it's not one
+ * of the ones to be freed.
+ * ----------------
+ */
+void
+FreeExecutorState(EState *estate)
+{
+	/*
+	 * Shut down and free any remaining ExprContexts.  We do this
+	 * explicitly to ensure that any remaining shutdown callbacks get
+	 * called (since they might need to release resources that aren't
+	 * simply memory within the per-query memory context).
+	 */
+	while (estate->es_exprcontexts)
+	{
+		FreeExprContext((ExprContext *) lfirst(estate->es_exprcontexts));
+		/* FreeExprContext removed the list link for us */
+	}
+	/*
+	 * Free the per-query memory context, thereby releasing all working
+	 * memory, including the EState node itself.
+	 */
+	MemoryContextDelete(estate->es_query_cxt);
 }
 
 /* ----------------
- *		MakeExprContext
+ *		CreateExprContext
+ *
+ *		Create a context for expression evaluation within an EState.
+ *
+ * An executor run may require multiple ExprContexts (we usually make one
+ * for each Plan node, and a separate one for per-output-tuple processing
+ * such as constraint checking).  Each ExprContext has its own "per-tuple"
+ * memory context.
  *
- *		Build an expression context for use outside normal plan-node cases.
- *		A fake scan-tuple slot can be supplied (pass NULL if not needed).
- *		A memory context sufficiently long-lived to use as fcache context
- *		must be supplied as well.
+ * Note we make no assumption about the caller's memory context.
  * ----------------
  */
 ExprContext *
-MakeExprContext(TupleTableSlot *slot,
-				MemoryContext queryContext)
+CreateExprContext(EState *estate)
 {
-	ExprContext *econtext = makeNode(ExprContext);
+	ExprContext *econtext;
+	MemoryContext oldcontext;
 
-	econtext->ecxt_scantuple = slot;
+	/* Create the ExprContext node within the per-query memory context */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	econtext = makeNode(ExprContext);
+
+	/* Initialize fields of ExprContext */
+	econtext->ecxt_scantuple = NULL;
 	econtext->ecxt_innertuple = NULL;
 	econtext->ecxt_outertuple = NULL;
-	econtext->ecxt_per_query_memory = queryContext;
+
+	econtext->ecxt_per_query_memory = estate->es_query_cxt;
 
 	/*
-	 * We make the temporary context a child of current working context,
-	 * not of the specified queryContext.  This seems reasonable but I'm
-	 * not totally sure about it...
-	 *
-	 * Expression contexts made via this routine typically don't live long
-	 * enough to get reset, so specify a minsize of 0.	That avoids
-	 * alloc'ing any memory in the common case where expr eval doesn't use
-	 * any.
+	 * Create working memory for expression evaluation in this context.
 	 */
 	econtext->ecxt_per_tuple_memory =
-		AllocSetContextCreate(CurrentMemoryContext,
-							  "TempExprContext",
-							  0,
+		AllocSetContextCreate(estate->es_query_cxt,
+							  "ExprContext",
+							  ALLOCSET_DEFAULT_MINSIZE,
 							  ALLOCSET_DEFAULT_INITSIZE,
 							  ALLOCSET_DEFAULT_MAXSIZE);
-	econtext->ecxt_param_exec_vals = NULL;
-	econtext->ecxt_param_list_info = NULL;
+
+	econtext->ecxt_param_exec_vals = estate->es_param_exec_vals;
+	econtext->ecxt_param_list_info = estate->es_param_list_info;
+
 	econtext->ecxt_aggvalues = NULL;
 	econtext->ecxt_aggnulls = NULL;
+
+	econtext->domainValue_datum = (Datum) 0;
+	econtext->domainValue_isNull = true;
+
+	econtext->ecxt_estate = estate;
+
 	econtext->ecxt_callbacks = NULL;
 
+	/*
+	 * Link the ExprContext into the EState to ensure it is shut down
+	 * when the EState is freed.  Because we use lcons(), shutdowns will
+	 * occur in reverse order of creation, which may not be essential
+	 * but can't hurt.
+	 */
+	estate->es_exprcontexts = lcons(econtext, estate->es_exprcontexts);
+
+	MemoryContextSwitchTo(oldcontext);
+
 	return econtext;
 }
 
-/*
- * Free an ExprContext made by MakeExprContext, including the temporary
- * context used for expression evaluation.	Note this will cause any
- * pass-by-reference expression result to go away!
+/* ----------------
+ *		FreeExprContext
+ *
+ *		Free an expression context, including calling any remaining
+ *		shutdown callbacks.
+ *
+ * Since we free the temporary context used for expression evaluation,
+ * any previously computed pass-by-reference expression result will go away!
+ *
+ * Note we make no assumption about the caller's memory context.
+ * ----------------
  */
 void
 FreeExprContext(ExprContext *econtext)
 {
+	EState	   *estate;
+
 	/* Call any registered callbacks */
 	ShutdownExprContext(econtext);
 	/* And clean up the memory used */
 	MemoryContextDelete(econtext->ecxt_per_tuple_memory);
+	/* Unlink self from owning EState */
+	estate = econtext->ecxt_estate;
+	estate->es_exprcontexts = lremove(econtext, estate->es_exprcontexts);
+	/* And delete the ExprContext node */
 	pfree(econtext);
 }
 
 /*
  * Build a per-output-tuple ExprContext for an EState.
  *
- * This is normally invoked via GetPerTupleExprContext() macro.
+ * This is normally invoked via GetPerTupleExprContext() macro,
+ * not directly.
  */
 ExprContext *
 MakePerTupleExprContext(EState *estate)
 {
 	if (estate->es_per_tuple_exprcontext == NULL)
-	{
-		MemoryContext oldContext;
+		estate->es_per_tuple_exprcontext = CreateExprContext(estate);
 
-		oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
-		estate->es_per_tuple_exprcontext =
-			MakeExprContext(NULL, estate->es_query_cxt);
-		MemoryContextSwitchTo(oldContext);
-	}
 	return estate->es_per_tuple_exprcontext;
 }
 
+
 /* ----------------------------------------------------------------
- *		Result slot tuple type and ProjectionInfo support
+ *				 miscellaneous node-init support functions
+ *
+ * Note: all of these are expected to be called with CurrentMemoryContext
+ * equal to the per-query memory context.
  * ----------------------------------------------------------------
  */
 
 /* ----------------
+ *		ExecAssignExprContext
+ *
+ *		This initializes the ps_ExprContext field.  It is only necessary
+ *		to do this for nodes which use ExecQual or ExecProject
+ *		because those routines require an econtext.	Other nodes that
+ *		don't have to evaluate expressions don't need to do this.
+ * ----------------
+ */
+void
+ExecAssignExprContext(EState *estate, PlanState *planstate)
+{
+	planstate->ps_ExprContext = CreateExprContext(estate);
+}
+
+/* ----------------
  *		ExecAssignResultType
  * ----------------
  */
@@ -368,34 +502,12 @@ ExecAssignProjectionInfo(PlanState *planstate)
 
 
 /* ----------------
- *		ExecFreeProjectionInfo
- * ----------------
- */
-void
-ExecFreeProjectionInfo(PlanState *planstate)
-{
-	ProjectionInfo *projInfo;
-
-	/*
-	 * get projection info.  if NULL then this node has none so we just
-	 * return.
-	 */
-	projInfo = planstate->ps_ProjInfo;
-	if (projInfo == NULL)
-		return;
-
-	/*
-	 * clean up memory used.
-	 */
-	if (projInfo->pi_tupValue != NULL)
-		pfree(projInfo->pi_tupValue);
-
-	pfree(projInfo);
-	planstate->ps_ProjInfo = NULL;
-}
-
-/* ----------------
  *		ExecFreeExprContext
+ *
+ * A plan node's ExprContext should be freed explicitly during ExecEndNode
+ * because there may be shutdown callbacks to call.  (Other resources made
+ * by the above routines, such as projection info, don't need to be freed
+ * explicitly because they're just memory in the per-query memory context.)
  * ----------------
  */
 void
@@ -411,16 +523,8 @@ ExecFreeExprContext(PlanState *planstate)
 	if (econtext == NULL)
 		return;
 
-	/*
-	 * clean up any registered callbacks
-	 */
-	ShutdownExprContext(econtext);
+	FreeExprContext(econtext);
 
-	/*
-	 * clean up memory used.
-	 */
-	MemoryContextDelete(econtext->ecxt_per_tuple_memory);
-	pfree(econtext);
 	planstate->ps_ExprContext = NULL;
 }
 
@@ -612,7 +716,8 @@ ExecCloseIndices(ResultRelInfo *resultRelInfo)
 	}
 
 	/*
-	 * XXX should free indexInfo array here too.
+	 * XXX should free indexInfo array here too?  Currently we assume that
+	 * such stuff will be cleaned up automatically in FreeExecutorState.
 	 */
 }
 
@@ -674,16 +779,31 @@ ExecInsertIndexTuples(TupleTableSlot *slot,
 	for (i = 0; i < numIndices; i++)
 	{
 		IndexInfo  *indexInfo;
-		List	   *predicate;
 		InsertIndexResult result;
 
 		if (relationDescs[i] == NULL)
 			continue;
 
 		indexInfo = indexInfoArray[i];
-		predicate = indexInfo->ii_PredicateState;
-		if (predicate != NIL)
+
+		/* Check for partial index */
+		if (indexInfo->ii_Predicate != NIL)
 		{
+			List	   *predicate;
+
+			/*
+			 * If predicate state not set up yet, create it (in the
+			 * estate's per-query context)
+			 */
+			predicate = indexInfo->ii_PredicateState;
+			if (predicate == NIL)
+			{
+				predicate = (List *)
+					ExecPrepareExpr((Expr *) indexInfo->ii_Predicate,
+									estate);
+				indexInfo->ii_PredicateState = predicate;
+			}
+
 			/* Skip this index-update if the predicate isn't satisfied */
 			if (!ExecQual(predicate, econtext, false))
 				continue;
@@ -811,6 +931,17 @@ static void
 ShutdownExprContext(ExprContext *econtext)
 {
 	ExprContext_CB *ecxt_callback;
+	MemoryContext oldcontext;
+
+	/* Fast path in normal case where there's nothing to do. */
+	if (econtext->ecxt_callbacks == NULL)
+		return;
+
+	/*
+	 * Call the callbacks in econtext's per-tuple context.  This ensures
+	 * that any memory they might leak will get cleaned up.
+	 */
+	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
 
 	/*
 	 * Call each callback function in reverse registration order.
@@ -821,4 +952,6 @@ ShutdownExprContext(ExprContext *econtext)
 		(*ecxt_callback->function) (ecxt_callback->arg);
 		pfree(ecxt_callback);
 	}
+
+	MemoryContextSwitchTo(oldcontext);
 }
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index 328aea5f079..d3ccf0dd905 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/functions.c,v 1.61 2002/12/05 15:50:32 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/functions.c,v 1.62 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -284,7 +284,8 @@ postquel_end(execution_state *es)
 	if (es->qd->operation != CMD_UTILITY)
 		ExecutorEnd(es->qd);
 
-	pfree(es->qd);
+	FreeQueryDesc(es->qd);
+
 	es->qd = NULL;
 
 	es->status = F_EXEC_DONE;
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index e6ba3887630..769e88a8397 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -45,7 +45,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.100 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.101 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1392,8 +1392,6 @@ ExecEndAgg(AggState *node)
 			tuplesort_end(peraggstate->sortstate);
 	}
 
-	ExecFreeProjectionInfo(&node->ss.ps);
-
 	/*
 	 * Free both the expr contexts.
 	 */
@@ -1401,18 +1399,13 @@ ExecEndAgg(AggState *node)
 	node->ss.ps.ps_ExprContext = node->tmpcontext;
 	ExecFreeExprContext(&node->ss.ps);
 
+	/* clean up tuple table */
+	ExecClearTuple(node->ss.ss_ScanTupleSlot);
+
 	MemoryContextDelete(node->aggcontext);
 
 	outerPlan = outerPlanState(node);
 	ExecEndNode(outerPlan);
-
-	/* clean up tuple table */
-	ExecClearTuple(node->ss.ss_ScanTupleSlot);
-	if (node->grp_firstTuple != NULL)
-	{
-		heap_freetuple(node->grp_firstTuple);
-		node->grp_firstTuple = NULL;
-	}
 }
 
 void
diff --git a/src/backend/executor/nodeFunctionscan.c b/src/backend/executor/nodeFunctionscan.c
index d0bf78631da..78f66523d51 100644
--- a/src/backend/executor/nodeFunctionscan.c
+++ b/src/backend/executor/nodeFunctionscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeFunctionscan.c,v 1.15 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeFunctionscan.c,v 1.16 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -273,9 +273,8 @@ void
 ExecEndFunctionScan(FunctionScanState *node)
 {
 	/*
-	 * Free the projection info and the scan attribute info
+	 * Free the exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->ss.ps);
 	ExecFreeExprContext(&node->ss.ps);
 
 	/*
diff --git a/src/backend/executor/nodeGroup.c b/src/backend/executor/nodeGroup.c
index 8bb72ba3438..58f6c1b34e9 100644
--- a/src/backend/executor/nodeGroup.c
+++ b/src/backend/executor/nodeGroup.c
@@ -15,7 +15,7 @@
  *	  locate group boundaries.
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeGroup.c,v 1.52 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeGroup.c,v 1.53 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -218,19 +218,13 @@ ExecEndGroup(GroupState *node)
 {
 	PlanState  *outerPlan;
 
-	ExecFreeProjectionInfo(&node->ss.ps);
 	ExecFreeExprContext(&node->ss.ps);
 
-	outerPlan = outerPlanState(node);
-	ExecEndNode(outerPlan);
-
 	/* clean up tuple table */
 	ExecClearTuple(node->ss.ss_ScanTupleSlot);
-	if (node->grp_firstTuple != NULL)
-	{
-		heap_freetuple(node->grp_firstTuple);
-		node->grp_firstTuple = NULL;
-	}
+
+	outerPlan = outerPlanState(node);
+	ExecEndNode(outerPlan);
 }
 
 void
diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c
index 45ba826317d..efdd3b3cabb 100644
--- a/src/backend/executor/nodeHash.c
+++ b/src/backend/executor/nodeHash.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.70 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.71 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -179,10 +179,8 @@ ExecEndHash(HashState *node)
 	PlanState  *outerPlan;
 
 	/*
-	 * free projection info.  no need to free result type info because
-	 * that came from the outer plan...
+	 * free exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->ps);
 	ExecFreeExprContext(&node->ps);
 
 	/*
diff --git a/src/backend/executor/nodeHashjoin.c b/src/backend/executor/nodeHashjoin.c
index 07de8703812..8f899b577d7 100644
--- a/src/backend/executor/nodeHashjoin.c
+++ b/src/backend/executor/nodeHashjoin.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.44 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.45 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -456,24 +456,22 @@ ExecEndHashJoin(HashJoinState *node)
 	}
 
 	/*
-	 * Free the projection info and the scan attribute info
+	 * Free the exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->js.ps);
 	ExecFreeExprContext(&node->js.ps);
 
 	/*
-	 * clean up subtrees
-	 */
-	ExecEndNode(outerPlanState(node));
-	ExecEndNode(innerPlanState(node));
-
-	/*
 	 * clean out the tuple table
 	 */
 	ExecClearTuple(node->js.ps.ps_ResultTupleSlot);
 	ExecClearTuple(node->hj_OuterTupleSlot);
 	ExecClearTuple(node->hj_HashTupleSlot);
 
+	/*
+	 * clean up subtrees
+	 */
+	ExecEndNode(outerPlanState(node));
+	ExecEndNode(innerPlanState(node));
 }
 
 /* ----------------------------------------------------------------
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c
index 1e36e93113d..7b96723844b 100644
--- a/src/backend/executor/nodeIndexscan.c
+++ b/src/backend/executor/nodeIndexscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.74 2002/12/13 19:45:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.75 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -399,45 +399,39 @@ ExecIndexReScan(IndexScanState *node, ExprContext *exprCtxt)
 
 /* ----------------------------------------------------------------
  *		ExecEndIndexScan
- *
- * old comments
- *		Releases any storage allocated through C routines.
- *		Returns nothing.
  * ----------------------------------------------------------------
  */
 void
 ExecEndIndexScan(IndexScanState *node)
 {
-	ExprState ***runtimeKeyInfo;
-	ScanKey    *scanKeys;
-	int		   *numScanKeys;
 	int			numIndices;
-	Relation	relation;
 	RelationPtr indexRelationDescs;
 	IndexScanDescPtr indexScanDescs;
+	Relation	relation;
 	int			i;
 
-	runtimeKeyInfo = node->iss_RuntimeKeyInfo;
-
 	/*
 	 * extract information from the node
 	 */
 	numIndices = node->iss_NumIndices;
-	scanKeys = node->iss_ScanKeys;
-	numScanKeys = node->iss_NumScanKeys;
 	indexRelationDescs = node->iss_RelationDescs;
 	indexScanDescs = node->iss_ScanDescs;
 	relation = node->ss.ss_currentRelation;
 
 	/*
-	 * Free the projection info and the scan attribute info
+	 * Free the exprcontext(s)
 	 */
-	ExecFreeProjectionInfo(&node->ss.ps);
 	ExecFreeExprContext(&node->ss.ps);
 	if (node->iss_RuntimeContext)
 		FreeExprContext(node->iss_RuntimeContext);
 
 	/*
+	 * clear out tuple table slots
+	 */
+	ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
+	ExecClearTuple(node->ss.ss_ScanTupleSlot);
+
+	/*
 	 * close the index relations
 	 */
 	for (i = 0; i < numIndices; i++)
@@ -458,36 +452,6 @@ ExecEndIndexScan(IndexScanState *node)
 	 * locking, however.)
 	 */
 	heap_close(relation, NoLock);
-
-	/*
-	 * free the scan keys used in scanning the indices
-	 */
-	for (i = 0; i < numIndices; i++)
-	{
-		if (scanKeys[i] != NULL)
-			pfree(scanKeys[i]);
-	}
-	pfree(scanKeys);
-	pfree(numScanKeys);
-
-	if (runtimeKeyInfo)
-	{
-		for (i = 0; i < numIndices; i++)
-		{
-			if (runtimeKeyInfo[i] != NULL)
-				pfree(runtimeKeyInfo[i]);
-		}
-		pfree(runtimeKeyInfo);
-	}
-
-	/*
-	 * clear out tuple table slots
-	 */
-	ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
-	ExecClearTuple(node->ss.ss_ScanTupleSlot);
-	pfree(node->iss_RelationDescs);
-	pfree(node->iss_ScanDescs);
-	pfree(node);
 }
 
 /* ----------------------------------------------------------------
diff --git a/src/backend/executor/nodeLimit.c b/src/backend/executor/nodeLimit.c
index 6abd83de8aa..39d09331ce2 100644
--- a/src/backend/executor/nodeLimit.c
+++ b/src/backend/executor/nodeLimit.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeLimit.c,v 1.13 2002/12/13 19:45:54 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeLimit.c,v 1.14 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -349,10 +349,10 @@ ExecEndLimit(LimitState *node)
 {
 	ExecFreeExprContext(&node->ps);
 
-	ExecEndNode(outerPlanState(node));
-
 	/* clean up tuple table */
 	ExecClearTuple(node->ps.ps_ResultTupleSlot);
+
+	ExecEndNode(outerPlanState(node));
 }
 
 
diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c
index cf7ca89f4a9..a1725901a7c 100644
--- a/src/backend/executor/nodeMaterial.c
+++ b/src/backend/executor/nodeMaterial.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeMaterial.c,v 1.39 2002/12/05 15:50:33 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeMaterial.c,v 1.40 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -197,16 +197,16 @@ ExecEndMaterial(MaterialState *node)
 	ExecClearTuple(node->ss.ss_ScanTupleSlot);
 
 	/*
-	 * shut down the subplan
-	 */
-	ExecEndNode(outerPlanState(node));
-
-	/*
 	 * Release tuplestore resources
 	 */
 	if (node->tuplestorestate != NULL)
 		tuplestore_end((Tuplestorestate *) node->tuplestorestate);
 	node->tuplestorestate = NULL;
+
+	/*
+	 * shut down the subplan
+	 */
+	ExecEndNode(outerPlanState(node));
 }
 
 /* ----------------------------------------------------------------
diff --git a/src/backend/executor/nodeMergejoin.c b/src/backend/executor/nodeMergejoin.c
index 1bb5878d819..af6cd8d6f3f 100644
--- a/src/backend/executor/nodeMergejoin.c
+++ b/src/backend/executor/nodeMergejoin.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.54 2002/12/13 19:45:54 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.55 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1551,23 +1551,22 @@ ExecEndMergeJoin(MergeJoinState *node)
 			   "ending node processing");
 
 	/*
-	 * Free the projection info and the scan attribute info
+	 * Free the exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->js.ps);
 	ExecFreeExprContext(&node->js.ps);
 
 	/*
-	 * shut down the subplans
-	 */
-	ExecEndNode(innerPlanState(node));
-	ExecEndNode(outerPlanState(node));
-
-	/*
 	 * clean out the tuple table
 	 */
 	ExecClearTuple(node->js.ps.ps_ResultTupleSlot);
 	ExecClearTuple(node->mj_MarkedTupleSlot);
 
+	/*
+	 * shut down the subplans
+	 */
+	ExecEndNode(innerPlanState(node));
+	ExecEndNode(outerPlanState(node));
+
 	MJ1_printf("ExecEndMergeJoin: %s\n",
 			   "node processing ended");
 }
diff --git a/src/backend/executor/nodeNestloop.c b/src/backend/executor/nodeNestloop.c
index 452ed7d70c3..917a7011cbf 100644
--- a/src/backend/executor/nodeNestloop.c
+++ b/src/backend/executor/nodeNestloop.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeNestloop.c,v 1.28 2002/12/13 19:45:55 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeNestloop.c,v 1.29 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -364,21 +364,20 @@ ExecEndNestLoop(NestLoopState *node)
 			   "ending node processing");
 
 	/*
-	 * Free the projection info
+	 * Free the exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->js.ps);
 	ExecFreeExprContext(&node->js.ps);
 
 	/*
-	 * close down subplans
+	 * clean out the tuple table
 	 */
-	ExecEndNode(outerPlanState(node));
-	ExecEndNode(innerPlanState(node));
+	ExecClearTuple(node->js.ps.ps_ResultTupleSlot);
 
 	/*
-	 * clean out the tuple table
+	 * close down subplans
 	 */
-	ExecClearTuple(node->js.ps.ps_ResultTupleSlot);
+	ExecEndNode(outerPlanState(node));
+	ExecEndNode(innerPlanState(node));
 
 	NL1_printf("ExecEndNestLoop: %s\n",
 			   "node processing ended");
diff --git a/src/backend/executor/nodeResult.c b/src/backend/executor/nodeResult.c
index 3f2c9927e01..9ea75eb3ce7 100644
--- a/src/backend/executor/nodeResult.c
+++ b/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 1.23 2002/12/13 19:45:55 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeResult.c,v 1.24 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -248,9 +248,8 @@ void
 ExecEndResult(ResultState *node)
 {
 	/*
-	 * Free the projection info
+	 * Free the exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->ps);
 	ExecFreeExprContext(&node->ps);
 
 	/*
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c
index 6a7393795b2..6628a9eecbe 100644
--- a/src/backend/executor/nodeSeqscan.c
+++ b/src/backend/executor/nodeSeqscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSeqscan.c,v 1.40 2002/12/13 19:45:55 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSeqscan.c,v 1.41 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -264,23 +264,22 @@ ExecEndSeqScan(SeqScanState *node)
 	scanDesc = node->ss_currentScanDesc;
 
 	/*
-	 * Free the projection info and the scan attribute info
+	 * Free the exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->ps);
 	ExecFreeExprContext(&node->ps);
 
 	/*
-	 * close heap scan
-	 */
-	heap_endscan(scanDesc);
-
-	/*
 	 * clean out the tuple table
 	 */
 	ExecClearTuple(node->ps.ps_ResultTupleSlot);
 	ExecClearTuple(node->ss_ScanTupleSlot);
 
 	/*
+	 * close heap scan
+	 */
+	heap_endscan(scanDesc);
+
+	/*
 	 * close the heap relation.
 	 *
 	 * Currently, we do not release the AccessShareLock acquired by
diff --git a/src/backend/executor/nodeSetOp.c b/src/backend/executor/nodeSetOp.c
index a81a4a29d91..965a2a6466a 100644
--- a/src/backend/executor/nodeSetOp.c
+++ b/src/backend/executor/nodeSetOp.c
@@ -21,7 +21,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSetOp.c,v 1.7 2002/12/05 15:50:33 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSetOp.c,v 1.8 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -301,9 +301,9 @@ ExecEndSetOp(SetOpState *node)
 	ExecClearTuple(node->ps.ps_ResultTupleSlot);
 	node->ps.ps_OuterTupleSlot = NULL;
 
-	ExecEndNode(outerPlanState(node));
-
 	MemoryContextDelete(node->tempContext);
+
+	ExecEndNode(outerPlanState(node));
 }
 
 
diff --git a/src/backend/executor/nodeSort.c b/src/backend/executor/nodeSort.c
index e1b4db7a51d..a37583241fb 100644
--- a/src/backend/executor/nodeSort.c
+++ b/src/backend/executor/nodeSort.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSort.c,v 1.41 2002/12/05 15:50:33 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSort.c,v 1.42 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -285,17 +285,17 @@ ExecEndSort(SortState *node)
 	ExecClearTuple(node->ss.ss_ScanTupleSlot);
 
 	/*
-	 * shut down the subplan
-	 */
-	ExecEndNode(outerPlanState(node));
-
-	/*
 	 * Release tuplesort resources
 	 */
 	if (node->tuplesortstate != NULL)
 		tuplesort_end((Tuplesortstate *) node->tuplesortstate);
 	node->tuplesortstate = NULL;
 
+	/*
+	 * shut down the subplan
+	 */
+	ExecEndNode(outerPlanState(node));
+
 	SO1_printf("ExecEndSort: %s\n",
 			   "sort node shutdown");
 }
diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c
index 3a2ca974aee..2f5ab52e213 100644
--- a/src/backend/executor/nodeSubplan.c
+++ b/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 1.38 2002/12/14 00:17:50 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.39 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -47,9 +47,10 @@ ExecSubPlan(SubPlanState *node,
 
 	/*
 	 * We are probably in a short-lived expression-evaluation context.
-	 * Switch to longer-lived per-query context.
+	 * Switch to the child plan's per-query context for manipulating its
+	 * chgParam, calling ExecProcNode on it, etc.
 	 */
-	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
+	oldcontext = MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
 
 	if (subplan->setParam != NIL)
 		elog(ERROR, "ExecSubPlan: can't set parent params from subquery");
@@ -132,10 +133,13 @@ ExecSubPlan(SubPlanState *node,
 			 * ExecProcNode() call. node->curTuple keeps track of the
 			 * copied tuple for eventual freeing.
 			 */
+			MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
 			tup = heap_copytuple(tup);
 			if (node->curTuple)
 				heap_freetuple(node->curTuple);
 			node->curTuple = tup;
+			MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
+
 			result = heap_getattr(tup, col, tdesc, isNull);
 			/* keep scanning subplan to make sure there's only one tuple */
 			continue;
@@ -295,6 +299,7 @@ ExecInitSubPlan(SubPlanState *node, EState *estate)
 {
 	SubPlan	   *subplan = (SubPlan *) node->xprstate.expr;
 	EState	   *sp_estate;
+	MemoryContext oldcontext;
 
 	/*
 	 * Do access checking on the rangetable entries in the subquery.
@@ -303,15 +308,23 @@ ExecInitSubPlan(SubPlanState *node, EState *estate)
 	ExecCheckRTPerms(subplan->rtable, CMD_SELECT);
 
 	/*
-	 * initialize state
+	 * initialize my state
 	 */
 	node->needShutdown = false;
 	node->curTuple = NULL;
 
 	/*
 	 * create an EState for the subplan
+	 *
+	 * The subquery needs its own EState because it has its own rangetable.
+	 * It shares our Param ID space, however.  XXX if rangetable access were
+	 * done differently, the subquery could share our EState, which would
+	 * eliminate some thrashing about in this module...
 	 */
 	sp_estate = CreateExecutorState();
+	node->sub_estate = sp_estate;
+
+	oldcontext = MemoryContextSwitchTo(sp_estate->es_query_cxt);
 
 	sp_estate->es_range_table = subplan->rtable;
 	sp_estate->es_param_list_info = estate->es_param_list_info;
@@ -322,12 +335,14 @@ ExecInitSubPlan(SubPlanState *node, EState *estate)
 	sp_estate->es_instrument = estate->es_instrument;
 
 	/*
-	 * Start up the subplan
+	 * Start up the subplan (this is a very cut-down form of InitPlan())
 	 */
 	node->planstate = ExecInitNode(subplan->plan, sp_estate);
 
 	node->needShutdown = true;	/* now we need to shutdown the subplan */
 
+	MemoryContextSwitchTo(oldcontext);
+
 	/*
 	 * If this plan is un-correlated or undirect correlated one and want
 	 * to set params for parent plan then prepare parameters.
@@ -376,10 +391,9 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
 	bool		found = false;
 
 	/*
-	 * We are probably in a short-lived expression-evaluation context.
-	 * Switch to longer-lived per-query context.
+	 * Must switch to child query's per-query memory context.
 	 */
-	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
+	oldcontext = MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
 
 	if (subLinkType == ANY_SUBLINK ||
 		subLinkType == ALL_SUBLINK)
@@ -415,15 +429,18 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
 		found = true;
 
 		/*
-		 * We need to copy the subplan's tuple in case any of the params
-		 * are pass-by-ref type --- the pointers stored in the param
-		 * structs will point at this copied tuple!  node->curTuple keeps
-		 * track of the copied tuple for eventual freeing.
+		 * We need to copy the subplan's tuple into our own context,
+		 * in case any of the params are pass-by-ref type --- the pointers
+		 * stored in the param structs will point at this copied tuple!
+		 * node->curTuple keeps track of the copied tuple for eventual
+		 * freeing.
 		 */
+		MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
 		tup = heap_copytuple(tup);
 		if (node->curTuple)
 			heap_freetuple(node->curTuple);
 		node->curTuple = tup;
+		MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
 
 		foreach(lst, subplan->setParam)
 		{
@@ -460,7 +477,10 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
 
 	if (planstate->plan->extParam == NULL) /* un-correlated ... */
 	{
-		ExecEndNode(planstate);
+		ExecEndPlan(planstate, node->sub_estate);
+		/* mustn't free context while still in it... */
+		MemoryContextSwitchTo(oldcontext);
+		FreeExecutorState(node->sub_estate);
 		node->needShutdown = false;
 	}
 
@@ -476,7 +496,12 @@ ExecEndSubPlan(SubPlanState *node)
 {
 	if (node->needShutdown)
 	{
-		ExecEndNode(node->planstate);
+		MemoryContext oldcontext;
+
+		oldcontext = MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
+		ExecEndPlan(node->planstate, node->sub_estate);
+		MemoryContextSwitchTo(oldcontext);
+		FreeExecutorState(node->sub_estate);
 		node->needShutdown = false;
 	}
 	if (node->curTuple)
diff --git a/src/backend/executor/nodeSubqueryscan.c b/src/backend/executor/nodeSubqueryscan.c
index 68291ba6e34..4466ef34219 100644
--- a/src/backend/executor/nodeSubqueryscan.c
+++ b/src/backend/executor/nodeSubqueryscan.c
@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.15 2002/12/13 19:45:55 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.16 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,7 @@ SubqueryNext(SubqueryScanState *node)
 	EState	   *estate;
 	ScanDirection direction;
 	TupleTableSlot *slot;
+	MemoryContext oldcontext;
 
 	/*
 	 * get information from the estate and scan state
@@ -66,12 +67,17 @@ SubqueryNext(SubqueryScanState *node)
 	 */
 
 	/*
-	 * get the next tuple from the sub-query
+	 * Get the next tuple from the sub-query.  We have to be careful to
+	 * run it in its appropriate memory context.
 	 */
 	node->sss_SubEState->es_direction = direction;
 
+	oldcontext = MemoryContextSwitchTo(node->sss_SubEState->es_query_cxt);
+
 	slot = ExecProcNode(node->subplan);
 
+	MemoryContextSwitchTo(oldcontext);
+
 	node->ss.ss_ScanTupleSlot = slot;
 
 	return slot;
@@ -106,6 +112,7 @@ ExecInitSubqueryScan(SubqueryScan *node, EState *estate)
 	SubqueryScanState *subquerystate;
 	RangeTblEntry *rte;
 	EState	   *sp_estate;
+	MemoryContext oldcontext;
 
 	/*
 	 * SubqueryScan should not have any "normal" children.
@@ -152,9 +159,17 @@ ExecInitSubqueryScan(SubqueryScan *node, EState *estate)
 	rte = rt_fetch(node->scan.scanrelid, estate->es_range_table);
 	Assert(rte->rtekind == RTE_SUBQUERY);
 
+	/*
+	 * The subquery needs its own EState because it has its own rangetable.
+	 * It shares our Param ID space, however.  XXX if rangetable access were
+	 * done differently, the subquery could share our EState, which would
+	 * eliminate some thrashing about in this module...
+	 */
 	sp_estate = CreateExecutorState();
 	subquerystate->sss_SubEState = sp_estate;
 
+	oldcontext = MemoryContextSwitchTo(sp_estate->es_query_cxt);
+
 	sp_estate->es_range_table = rte->subquery->rtable;
 	sp_estate->es_param_list_info = estate->es_param_list_info;
 	sp_estate->es_param_exec_vals = estate->es_param_exec_vals;
@@ -163,8 +178,13 @@ ExecInitSubqueryScan(SubqueryScan *node, EState *estate)
 	sp_estate->es_snapshot = estate->es_snapshot;
 	sp_estate->es_instrument = estate->es_instrument;
 
+	/*
+	 * Start up the subplan (this is a very cut-down form of InitPlan())
+	 */
 	subquerystate->subplan = ExecInitNode(node->subplan, sp_estate);
 
+	MemoryContextSwitchTo(oldcontext);
+
 	subquerystate->ss.ss_ScanTupleSlot = NULL;
 	subquerystate->ss.ps.ps_TupFromTlist = false;
 
@@ -197,10 +217,11 @@ ExecCountSlotsSubqueryScan(SubqueryScan *node)
 void
 ExecEndSubqueryScan(SubqueryScanState *node)
 {
+	MemoryContext oldcontext;
+
 	/*
-	 * Free the projection info and the scan attribute info
+	 * Free the exprcontext
 	 */
-	ExecFreeProjectionInfo(&node->ss.ps);
 	ExecFreeExprContext(&node->ss.ps);
 
 	/*
@@ -211,15 +232,13 @@ ExecEndSubqueryScan(SubqueryScanState *node)
 	/*
 	 * close down subquery
 	 */
-	ExecEndNode(node->subplan);
+	oldcontext = MemoryContextSwitchTo(node->sss_SubEState->es_query_cxt);
 
-	/*
-	 * clean up subquery's tuple table
-	 */
-	node->ss.ss_ScanTupleSlot = NULL;
-	ExecDropTupleTable(node->sss_SubEState->es_tupleTable, true);
+	ExecEndPlan(node->subplan, node->sss_SubEState);
 
-	/* XXX we seem to be leaking the sub-EState... */
+	MemoryContextSwitchTo(oldcontext);
+
+	FreeExecutorState(node->sss_SubEState);
 }
 
 /* ----------------------------------------------------------------
@@ -232,12 +251,17 @@ void
 ExecSubqueryReScan(SubqueryScanState *node, ExprContext *exprCtxt)
 {
 	EState	   *estate;
+	MemoryContext oldcontext;
 
 	estate = node->ss.ps.state;
 
+	oldcontext = MemoryContextSwitchTo(node->sss_SubEState->es_query_cxt);
+
 	/*
 	 * ExecReScan doesn't know about my subplan, so I have to do
-	 * changed-parameter signaling myself.
+	 * changed-parameter signaling myself.  This is just as well,
+	 * because the subplan has its own memory context in which its
+	 * chgParam lists live.
 	 */
 	if (node->ss.ps.chgParam != NULL)
 		SetChangedParamList(node->subplan, node->ss.ps.chgParam);
@@ -249,5 +273,7 @@ ExecSubqueryReScan(SubqueryScanState *node, ExprContext *exprCtxt)
 	if (node->subplan->chgParam == NULL)
 		ExecReScan(node->subplan, NULL);
 
+	MemoryContextSwitchTo(oldcontext);
+
 	node->ss.ss_ScanTupleSlot = NULL;
 }
diff --git a/src/backend/executor/nodeTidscan.c b/src/backend/executor/nodeTidscan.c
index ba2793407ce..7e35bc07cd7 100644
--- a/src/backend/executor/nodeTidscan.c
+++ b/src/backend/executor/nodeTidscan.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeTidscan.c,v 1.29 2002/12/13 19:45:56 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeTidscan.c,v 1.30 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -278,19 +278,8 @@ void
 ExecEndTidScan(TidScanState *node)
 {
 	/*
-	 * extract information from the node
+	 * Free the exprcontext
 	 */
-	if (node && node->tss_TidList)
-		pfree(node->tss_TidList);
-
-	/*
-	 * Free the projection info and the scan attribute info
-	 *
-	 * Note: we don't ExecFreeResultType(scanstate) because the rule manager
-	 * depends on the tupType returned by ExecMain().  So for now, this is
-	 * freed at end-transaction time.  -cim 6/2/91
-	 */
-	ExecFreeProjectionInfo(&node->ss.ps);
 	ExecFreeExprContext(&node->ss.ps);
 
 	/*
diff --git a/src/backend/executor/nodeUnique.c b/src/backend/executor/nodeUnique.c
index 88b08061f99..415594f92c4 100644
--- a/src/backend/executor/nodeUnique.c
+++ b/src/backend/executor/nodeUnique.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeUnique.c,v 1.35 2002/12/05 15:50:34 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeUnique.c,v 1.36 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -194,15 +194,10 @@ ExecEndUnique(UniqueState *node)
 {
 	/* clean up tuple table */
 	ExecClearTuple(node->ps.ps_ResultTupleSlot);
-	if (node->priorTuple != NULL)
-	{
-		heap_freetuple(node->priorTuple);
-		node->priorTuple = NULL;
-	}
-
-	ExecEndNode(outerPlanState(node));
 
 	MemoryContextDelete(node->tempContext);
+
+	ExecEndNode(outerPlanState(node));
 }
 
 
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 147becf6ed8..cde9ab6ff6e 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.79 2002/12/05 15:50:34 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/spi.c,v 1.80 2002/12/15 16:17:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1287,23 +1287,23 @@ _SPI_pquery(QueryDesc *queryDesc, bool runit, int tcount)
 			elog(FATAL, "SPI_select: # of processed tuples check failed");
 	}
 
-	ExecutorEnd(queryDesc);
-
-#ifdef SPI_EXECUTOR_STATS
-	if (ShowExecutorStats)
-		ShowUsage("SPI EXECUTOR STATS");
-#endif
-
 	if (dest == SPI)
 	{
 		SPI_processed = _SPI_current->processed;
 		SPI_lastoid = save_lastoid;
 		SPI_tuptable = _SPI_current->tuptable;
 	}
-	queryDesc->dest = dest;
 
-	return res;
+	ExecutorEnd(queryDesc);
+
+	FreeQueryDesc(queryDesc);
+
+#ifdef SPI_EXECUTOR_STATS
+	if (ShowExecutorStats)
+		ShowUsage("SPI EXECUTOR STATS");
+#endif
 
+	return res;
 }
 
 /*
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index e4eedd11790..984c930e3a6 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.128 2002/12/13 19:45:56 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.129 2002/12/15 16:17:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1132,7 +1132,8 @@ pred_test_simple_clause(Expr *predicate, Node *clause)
 	HeapTuple	tuple;
 	ScanKeyData entry[1];
 	Form_pg_amop aform;
-	ExprContext *econtext;
+	EState	   *estate;
+	MemoryContext oldcontext;
 
 	/* First try the equal() test */
 	if (equal((Node *) predicate, clause))
@@ -1267,20 +1268,33 @@ pred_test_simple_clause(Expr *predicate, Node *clause)
 	ReleaseSysCache(tuple);
 
 	/*
-	 * 5. Evaluate the test
+	 * 5. Evaluate the test.  For this we need an EState.
 	 */
+	estate = CreateExecutorState();
+
+	/* We can use the estate's working context to avoid memory leaks. */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	/* Build expression tree */
 	test_expr = make_opclause(test_op,
 							  BOOLOID,
 							  false,
 							  (Expr *) clause_const,
 							  (Expr *) pred_const);
-	set_opfuncid((OpExpr *) test_expr);
-	test_exprstate = ExecInitExpr(test_expr, NULL);
 
-	econtext = MakeExprContext(NULL, CurrentMemoryContext);
-	test_result = ExecEvalExprSwitchContext(test_exprstate, econtext,
+	/* Prepare it for execution */
+	test_exprstate = ExecPrepareExpr(test_expr, estate);
+
+	/* And execute it. */
+	test_result = ExecEvalExprSwitchContext(test_exprstate,
+											GetPerTupleExprContext(estate),
 											&isNull, NULL);
-	FreeExprContext(econtext);
+
+	/* Get back to outer memory context */
+	MemoryContextSwitchTo(oldcontext);
+
+	/* Release all the junk we just created */
+	FreeExecutorState(estate);
 
 	if (isNull)
 	{
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 1d87afdc42f..4c87a95c3b1 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.119 2002/12/14 00:17:59 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.120 2002/12/15 16:17:50 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1684,7 +1684,8 @@ evaluate_function(Oid funcid, List *args, HeapTuple func_tuple)
 	bool		has_null_input = false;
 	FuncExpr   *newexpr;
 	ExprState  *newexprstate;
-	ExprContext *econtext;
+	EState	   *estate;
+	MemoryContext oldcontext;
 	Datum		const_val;
 	bool		const_is_null;
 	List	   *arg;
@@ -1729,7 +1730,14 @@ evaluate_function(Oid funcid, List *args, HeapTuple func_tuple)
 	 *
 	 * We use the executor's routine ExecEvalExpr() to avoid duplication of
 	 * code and ensure we get the same result as the executor would get.
-	 *
+	 * To use the executor, we need an EState.
+	 */
+	estate = CreateExecutorState();
+
+	/* We can use the estate's working context to avoid memory leaks. */
+	oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+
+	/*
 	 * Build a new FuncExpr node containing the already-simplified arguments.
 	 */
 	newexpr = makeNode(FuncExpr);
@@ -1739,27 +1747,35 @@ evaluate_function(Oid funcid, List *args, HeapTuple func_tuple)
 	newexpr->funcformat = COERCE_EXPLICIT_CALL;	/* doesn't matter */
 	newexpr->args = args;
 
-	/* Get info needed about result datatype */
-	get_typlenbyval(result_typeid, &resultTypLen, &resultTypByVal);
+	/*
+	 * Prepare it for execution.
+	 */
+	newexprstate = ExecPrepareExpr((Expr *) newexpr, estate);
 
 	/*
-	 * It is OK to use a dummy econtext because none of the
+	 * And evaluate it.
+	 *
+	 * It is OK to use a default econtext because none of the
 	 * ExecEvalExpr() code used in this situation will use econtext.  That
 	 * might seem fortuitous, but it's not so unreasonable --- a constant
 	 * expression does not depend on context, by definition, n'est ce pas?
 	 */
-	econtext = MakeExprContext(NULL, CurrentMemoryContext);
+	const_val = ExecEvalExprSwitchContext(newexprstate,
+										  GetPerTupleExprContext(estate),
+										  &const_is_null, NULL);
 
-	newexprstate = ExecInitExpr((Expr *) newexpr, NULL);
+	/* Get info needed about result datatype */
+	get_typlenbyval(result_typeid, &resultTypLen, &resultTypByVal);
 
-	const_val = ExecEvalExprSwitchContext(newexprstate, econtext,
-										  &const_is_null, NULL);
+	/* Get back to outer memory context */
+	MemoryContextSwitchTo(oldcontext);
 
 	/* Must copy result out of sub-context used by expression eval */
 	if (!const_is_null)
 		const_val = datumCopy(const_val, resultTypByVal, resultTypLen);
 
-	FreeExprContext(econtext);
+	/* Release all the junk we just created */
+	FreeExecutorState(estate);
 
 	/*
 	 * Make the constant result node.
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index 24d4aac8b2c..1e02e42193d 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/pquery.c,v 1.57 2002/12/05 15:50:35 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/pquery.c,v 1.58 2002/12/15 16:17:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -52,6 +52,18 @@ CreateQueryDesc(Query *parsetree,
 	return qd;
 }
 
+/*
+ * FreeQueryDesc
+ */
+void
+FreeQueryDesc(QueryDesc *qdesc)
+{
+	/* Can't be a live query */
+	Assert(qdesc->estate == NULL);
+	/* Only the QueryDesc itself need be freed */
+	pfree(qdesc);
+}
+
 /* ----------------
  *		PreparePortal
  * ----------------
@@ -152,9 +164,8 @@ ProcessQuery(Query *parsetree,
 												 * QueryDesc */
 
 		/*
-		 * We stay in portal's memory context for now, so that query desc,
-		 * exec state, and plan startup info are also allocated in the portal
-		 * context.
+		 * We stay in portal's memory context for now, so that query desc
+		 * is also allocated in the portal context.
 		 */
 	}
 
@@ -231,4 +242,6 @@ ProcessQuery(Query *parsetree,
 	 * Now, we close down all the scans and free allocated resources.
 	 */
 	ExecutorEnd(queryDesc);
+
+	FreeQueryDesc(queryDesc);
 }
diff --git a/src/include/executor/execdesc.h b/src/include/executor/execdesc.h
index 9a95551d7c8..27148bb1d86 100644
--- a/src/include/executor/execdesc.h
+++ b/src/include/executor/execdesc.h
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execdesc.h,v 1.21 2002/12/05 15:50:36 tgl Exp $
+ * $Id: execdesc.h,v 1.22 2002/12/15 16:17:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -50,4 +50,6 @@ extern QueryDesc *CreateQueryDesc(Query *parsetree, Plan *plantree,
 								  ParamListInfo params,
 								  bool doInstrument);
 
+extern void FreeQueryDesc(QueryDesc *qdesc);
+
 #endif   /* EXECDESC_H  */
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 9b7af6d36fb..571f35c64e3 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: executor.h,v 1.83 2002/12/14 00:17:59 tgl Exp $
+ * $Id: executor.h,v 1.84 2002/12/15 16:17:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -54,8 +54,8 @@ extern void ExecutorStart(QueryDesc *queryDesc);
 extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc,
 			ScanDirection direction, long count);
 extern void ExecutorEnd(QueryDesc *queryDesc);
-extern EState *CreateExecutorState(void);
 extern void ExecCheckRTPerms(List *rangeTable, CmdType operation);
+extern void ExecEndPlan(PlanState *planstate, EState *estate);
 extern void ExecConstraints(const char *caller, ResultRelInfo *resultRelInfo,
 				TupleTableSlot *slot, EState *estate);
 extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti,
@@ -93,6 +93,7 @@ extern Datum ExecEvalExprSwitchContext(ExprState *expression, ExprContext *econt
 						  bool *isNull, ExprDoneCond *isDone);
 extern ExprState *ExecInitExpr(Expr *node, PlanState *parent);
 extern SubPlanState *ExecInitExprInitPlan(SubPlan *node, PlanState *parent);
+extern ExprState *ExecPrepareExpr(Expr *node, EState *estate);
 extern bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull);
 extern int	ExecTargetListLength(List *targetlist);
 extern int	ExecCleanTargetListLength(List *targetlist);
@@ -157,23 +158,9 @@ extern void end_tup_output(TupOutputState *tstate);
 /*
  * prototypes from functions in execUtils.c
  */
-extern void ResetTupleCount(void);
-extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
-extern void ExecAssignResultType(PlanState *planstate,
-					 TupleDesc tupDesc, bool shouldFree);
-extern void ExecAssignResultTypeFromOuterPlan(PlanState *planstate);
-extern void ExecAssignResultTypeFromTL(PlanState *planstate);
-extern TupleDesc ExecGetResultType(PlanState *planstate);
-extern void ExecAssignProjectionInfo(PlanState *planstate);
-extern void ExecFreeProjectionInfo(PlanState *planstate);
-extern void ExecFreeExprContext(PlanState *planstate);
-extern TupleDesc ExecGetScanType(ScanState *scanstate);
-extern void ExecAssignScanType(ScanState *scanstate,
-				   TupleDesc tupDesc, bool shouldFree);
-extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
-
-extern ExprContext *MakeExprContext(TupleTableSlot *slot,
-				MemoryContext queryContext);
+extern EState *CreateExecutorState(void);
+extern void FreeExecutorState(EState *estate);
+extern ExprContext *CreateExprContext(EState *estate);
 extern void FreeExprContext(ExprContext *econtext);
 
 #define ResetExprContext(econtext) \
@@ -197,6 +184,19 @@ extern ExprContext *MakePerTupleExprContext(EState *estate);
 			ResetExprContext((estate)->es_per_tuple_exprcontext); \
 	} while (0)
 
+extern void ExecAssignExprContext(EState *estate, PlanState *planstate);
+extern void ExecAssignResultType(PlanState *planstate,
+					 TupleDesc tupDesc, bool shouldFree);
+extern void ExecAssignResultTypeFromOuterPlan(PlanState *planstate);
+extern void ExecAssignResultTypeFromTL(PlanState *planstate);
+extern TupleDesc ExecGetResultType(PlanState *planstate);
+extern void ExecAssignProjectionInfo(PlanState *planstate);
+extern void ExecFreeExprContext(PlanState *planstate);
+extern TupleDesc ExecGetScanType(ScanState *scanstate);
+extern void ExecAssignScanType(ScanState *scanstate,
+				   TupleDesc tupDesc, bool shouldFree);
+extern void ExecAssignScanTypeFromOuterPlan(ScanState *scanstate);
+
 extern void ExecOpenIndices(ResultRelInfo *resultRelInfo);
 extern void ExecCloseIndices(ResultRelInfo *resultRelInfo);
 extern void ExecInsertIndexTuples(TupleTableSlot *slot, ItemPointer tupleid,
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index f8e1f7cc4c9..65c5f23884d 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execnodes.h,v 1.85 2002/12/14 00:17:59 tgl Exp $
+ * $Id: execnodes.h,v 1.86 2002/12/15 16:17:56 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -81,14 +81,14 @@ typedef struct ExprContext_CB
  *		context.
  *
  *	There are two memory contexts associated with an ExprContext:
- *	* ecxt_per_query_memory is a relatively long-lived context (such as
- *	  TransactionCommandContext); typically it's the same context the
- *	  ExprContext node itself is allocated in.	This context can be
- *	  used for purposes such as storing function call cache info.
+ *	* ecxt_per_query_memory is a query-lifespan context, typically the same
+ *	  context the ExprContext node itself is allocated in.  This context
+ *	  can be used for purposes such as storing function call cache info.
  *	* ecxt_per_tuple_memory is a short-term context for expression results.
  *	  As the name suggests, it will typically be reset once per tuple,
  *	  before we begin to evaluate expressions for that tuple.  Each
  *	  ExprContext normally has its very own per-tuple memory context.
+ *
  *	CurrentMemoryContext should be set to ecxt_per_tuple_memory before
  *	calling ExecEvalExpr() --- see ExecEvalExprSwitchContext().
  * ----------------
@@ -118,6 +118,9 @@ typedef struct ExprContext
 	Datum		domainValue_datum;
 	bool		domainValue_isNull;
 
+	/* Link to containing EState */
+	struct EState *ecxt_estate;
+
 	/* Functions to call back when ExprContext is shut down */
 	ExprContext_CB *ecxt_callbacks;
 } ExprContext;
@@ -277,45 +280,43 @@ typedef struct ResultRelInfo
 /* ----------------
  *	  EState information
  *
- *		direction						direction of the scan
- *
- *		snapshot						time qual to use
- *
- *		range_table						array of scan relation information
- *
- *		result_relation information		for insert/update/delete queries
- *
- *		into_relation_descriptor		relation being retrieved "into"
- *
- *		param_list_info					information about Param values
- *
- *		tupleTable						this is a pointer to an array
- *										of pointers to tuples used by
- *										the executor at any given moment.
+ * Master working state for an Executor invocation
  * ----------------
  */
 typedef struct EState
 {
 	NodeTag		type;
-	ScanDirection es_direction;
-	Snapshot	es_snapshot;
-	List	   *es_range_table;
+
+	/* Basic state for all query types: */
+	ScanDirection es_direction;	/* current scan direction */
+	Snapshot	es_snapshot;	/* time qual to use */
+	List	   *es_range_table;	/* List of RangeTableEntrys */
+
+	/* Info about target table for insert/update/delete queries: */
 	ResultRelInfo *es_result_relations; /* array of ResultRelInfos */
 	int			es_num_result_relations;		/* length of array */
 	ResultRelInfo *es_result_relation_info;		/* currently active array
 												 * elt */
 	JunkFilter *es_junkFilter;	/* currently active junk filter */
-	Relation	es_into_relation_descriptor;
+	Relation	es_into_relation_descriptor; /* for SELECT INTO */
+
+	/* Parameter info: */
 	ParamListInfo es_param_list_info;	/* values of external params */
 	ParamExecData *es_param_exec_vals;	/* values of internal params */
-	TupleTable	es_tupleTable;
+
+	/* Other working state: */
+	MemoryContext es_query_cxt; /* per-query context in which EState lives */
+
+	TupleTable	es_tupleTable;	/* Array of TupleTableSlots */
+
 	uint32		es_processed;	/* # of tuples processed */
 	Oid			es_lastoid;		/* last oid processed (by INSERT) */
 	List	   *es_rowMark;		/* not good place, but there is no other */
-	MemoryContext es_query_cxt; /* per-query context in which EState lives */
 
 	bool		es_instrument;	/* true requests runtime instrumentation */
 
+	List	   *es_exprcontexts; /* List of ExprContexts within EState */
+
 	/*
 	 * this ExprContext is for per-output-tuple operations, such as
 	 * constraint checks and index-value computations.	It will be reset
@@ -457,6 +458,7 @@ typedef struct BoolExprState
 typedef struct SubPlanState
 {
 	ExprState	xprstate;
+	EState	   *sub_estate;		/* subselect plan has its own EState */
 	struct PlanState *planstate; /* subselect plan's state tree */
 	bool		needShutdown;	/* TRUE = need to shutdown subplan */
 	HeapTuple	curTuple;		/* copy of most recent tuple from subplan */
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 8908a43a786..a569d9ee9da 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/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 1.74 2002/12/13 19:46:01 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.75 2002/12/15 16:17:58 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -3227,7 +3227,6 @@ exec_eval_simple_expr(PLpgSQL_execstate * estate,
 					  bool *isNull,
 					  Oid *rettype)
 {
-	_SPI_plan  *spi_plan = (_SPI_plan *) expr->plan;
 	Datum		retval;
 	PLpgSQL_var *var;
 	PLpgSQL_rec *rec;
@@ -3242,14 +3241,11 @@ exec_eval_simple_expr(PLpgSQL_execstate * estate,
 	ParamListInfo paramLI;
 
 	/*
-	 * Create a simple expression context to hold the arguments.
-	 *
-	 * NOTE: we pass the SPI plan's context as the query-lifetime context for
-	 * function cache nodes and suchlike allocations.  This is appropriate
-	 * because that's where the expression tree itself is, and the
-	 * function cache nodes must live as long as it does.
+	 * Create an expression context to hold the arguments and the result
+	 * of this expression evaluation.  This must be a child of the EState
+	 * we created in the SPI plan's context.
 	 */
-	econtext = MakeExprContext(NULL, spi_plan->plancxt);
+	econtext = CreateExprContext(expr->plan_simple_estate);
 
 	/*
 	 * Param list can live in econtext's temporary memory context.
@@ -3691,13 +3687,20 @@ exec_simple_check_plan(PLpgSQL_expr * expr)
 		return;
 
 	/*
-	 * Yes - this is a simple expression.  Prepare to execute it, and
-	 * stash away the result type.  Put the expression state tree in the
-	 * plan context so it will have appropriate lifespan.
+	 * Yes - this is a simple expression.  Prepare to execute it.
+	 * We need an EState and an expression state tree, which we'll put
+	 * into the plan context so they will have appropriate lifespan.
 	 */
 	oldcontext = MemoryContextSwitchTo(spi_plan->plancxt);
-	expr->plan_simple_expr = ExecInitExpr(tle->expr, NULL);
+
+	expr->plan_simple_estate = CreateExecutorState();
+
+	expr->plan_simple_expr = ExecPrepareExpr(tle->expr,
+											 expr->plan_simple_estate);
+
 	MemoryContextSwitchTo(oldcontext);
+
+	/* Also stash away the expression result type */
 	expr->plan_simple_type = exprType((Node *) tle->expr);
 }
 
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 945569b6f6a..f051c015721 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.30 2002/12/13 19:46:01 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.31 2002/12/15 16:17:59 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -166,6 +166,7 @@ typedef struct
 	char	   *query;
 	void	   *plan;
 	ExprState  *plan_simple_expr;
+	EState	   *plan_simple_estate;
 	Oid			plan_simple_type;
 	Oid		   *plan_argtypes;
 	int			nparams;