Changed ExecConstraints() and ExecRelCheck() to cache constraint

qualification trees in the execution state to avoid memory exhaustion
on INSERT, UPDATE and COPY to tables with check constraints. This
also speeds up those operations substantial because the nodeToString()
for the constraints ccbin is only performed once per query.

Jan

Author: Jan Wieck

src/backend/commands/copy.c

@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.63 1998/10/26 00:59:21 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.63.2.1 1999/02/07 16:50:51 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -402,6 +402,7 @@ CopyFrom(Relation rel, bool binary, bool oids, FILE *fp, char *delim)
 	Node	  **indexPred = NULL;
 	TupleDesc	rtupdesc;
 	ExprContext *econtext = NULL;
+	EState		*estate = makeNode(EState);
 
 #ifndef OMIT_PARTIAL_INDEX
 	TupleTable	tupleTable;
@@ -709,7 +710,7 @@ CopyFrom(Relation rel, bool binary, bool oids, FILE *fp, char *delim)
 			{
 				HeapTuple	newtuple;
 
-				newtuple = ExecConstraints("CopyFrom", rel, tuple);
+				newtuple = ExecConstraints("CopyFrom", rel, tuple, estate);
 
 				if (newtuple != tuple)
 				{

src/backend/executor/execMain.c

@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.58 1998/10/14 05:10:00 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.58.2.1 1999/02/07 16:50:52 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -965,7 +965,8 @@ ExecAppend(TupleTableSlot *slot,
 	{
 		HeapTuple	newtuple;
 
-		newtuple = ExecConstraints("ExecAppend", resultRelationDesc, tuple);
+		newtuple = ExecConstraints("ExecAppend", resultRelationDesc, 
+														tuple, estate);
 
 		if (newtuple != tuple)	/* modified by DEFAULT */
 		{
@@ -1148,7 +1149,8 @@ ExecReplace(TupleTableSlot *slot,
 	{
 		HeapTuple	newtuple;
 
-		newtuple = ExecConstraints("ExecReplace", resultRelationDesc, tuple);
+		newtuple = ExecConstraints("ExecReplace", resultRelationDesc, 
+														tuple, estate);
 
 		if (newtuple != tuple)	/* modified by DEFAULT */
 		{
@@ -1279,7 +1281,7 @@ ExecAttrDefault(Relation rel, HeapTuple tuple)
 #endif
 
 static char *
-ExecRelCheck(Relation rel, HeapTuple tuple)
+ExecRelCheck(Relation rel, HeapTuple tuple, EState *estate)
 {
 	int			ncheck = rel->rd_att->constr->num_check;
 	ConstrCheck *check = rel->rd_att->constr->check;
@@ -1312,14 +1314,24 @@ ExecRelCheck(Relation rel, HeapTuple tuple)
 	econtext->ecxt_param_exec_vals = NULL;		/* exec param values */
 	econtext->ecxt_range_table = rtlist;		/* range table */
 
+	if (estate->es_result_relation_constraints == NULL)
+	{
+		estate->es_result_relation_constraints =
+				(List **)palloc(ncheck * sizeof(List *));
+
+		for (i = 0; i < ncheck; i++)
+		{
+			qual = (List *) stringToNode(check[i].ccbin);
+			estate->es_result_relation_constraints[i] = qual;
+		}
+	}
+
 	for (i = 0; i < ncheck; i++)
 	{
-		qual = (List *) stringToNode(check[i].ccbin);
+		qual = estate->es_result_relation_constraints[i];
 
 		res = ExecQual(qual, econtext);
 
-		pfree(qual);
-
 		if (!res)
 			return check[i].ccname;
 	}
@@ -1335,7 +1347,7 @@ ExecRelCheck(Relation rel, HeapTuple tuple)
 }
 
 HeapTuple
-ExecConstraints(char *caller, Relation rel, HeapTuple tuple)
+ExecConstraints(char *caller, Relation rel, HeapTuple tuple, EState *estate)
 {
 	HeapTuple	newtuple = tuple;
 
@@ -1362,7 +1374,7 @@ ExecConstraints(char *caller, Relation rel, HeapTuple tuple)
 	{
 		char	   *failed;
 
-		if ((failed = ExecRelCheck(rel, tuple)) != NULL)
+		if ((failed = ExecRelCheck(rel, tuple, estate)) != NULL)
 			elog(ERROR, "%s: rejected due to CHECK constraint %s", caller, failed);
 	}
 

src/include/executor/executor.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: executor.h,v 1.27 1998/10/14 05:10:05 momjian Exp $
+ * $Id: executor.h,v 1.27.2.1 1999/02/07 16:50:54 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -85,7 +85,8 @@ extern HeapTuple ExecRemoveJunk(JunkFilter *junkfilter, TupleTableSlot *slot);
 extern TupleDesc ExecutorStart(QueryDesc *queryDesc, EState *estate);
 extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count);
 extern void ExecutorEnd(QueryDesc *queryDesc, EState *estate);
-extern HeapTuple ExecConstraints(char *caller, Relation rel, HeapTuple tuple);
+extern HeapTuple ExecConstraints(char *caller, Relation rel, HeapTuple tuple,
+													EState *estate);
 #ifdef QUERY_LIMIT
 extern int ExecutorLimit(int limit);
 extern int ExecutorGetLimit(void);

src/include/nodes/execnodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: execnodes.h,v 1.18 1998/09/01 04:36:35 momjian Exp $
+ * $Id: execnodes.h,v 1.18.2.1 1999/02/07 16:50:55 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -199,6 +199,7 @@ typedef struct EState
 	Snapshot	es_snapshot;
 	List	   *es_range_table;
 	RelationInfo *es_result_relation_info;
+	List	  **es_result_relation_constraints;
 	Relation	es_into_relation_descriptor;
 	ParamListInfo es_param_list_info;
 	ParamExecData *es_param_exec_vals;	/* this is for subselects */