Reset the per-output-tuple exprcontext each time through the main loop in

tglsfdc · tglsfdc · commit 3573c8346d4c · 2010-08-18T21:52:24.000Z
ExecModifyTable().  This avoids memory leakage when trigger functions leave
junk behind in that context (as they more or less must).  Problem and solution
identified by Dean Rasheed.

I'm a bit concerned about the longevity of this solution --- once a plan can
have multiple ModifyTable nodes, we are very possibly going to have to do
something different.  But it should hold up for 9.0.
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeModifyTable.c,v 1.8 2010/07/12 17:01:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeModifyTable.c,v 1.9 2010/08/18 21:52:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -682,6 +682,14 @@ ExecModifyTable(ModifyTableState *node)
 	 */
 	for (;;)
 	{
+		/*
+		 * Reset the per-output-tuple exprcontext.  This is needed because
+		 * triggers expect to use that context as workspace.  It's a bit ugly
+		 * to do this below the top level of the plan, however.  We might need
+		 * to rethink this later.
+		 */
+		ResetPerTupleExprContext(estate);
+
 		planSlot = ExecProcNode(subplanstate);
 
 		if (TupIsNull(planSlot))

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $PostgreSQL: pgsql/src/backend/executor/nodeModifyTable.c,v 1.8 2010/07/12 17:01:05 tgl Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/backend/executor/nodeModifyTable.c,v 1.9 2010/08/18 21:52:24 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -682,6 +682,14 @@ ExecModifyTable(ModifyTableState *node)`
`682`	`682`	`*/`
`683`	`683`	`for (;;)`
`684`	`684`	`{`
	`685`	`+ /*`
	`686`	`+ * Reset the per-output-tuple exprcontext. This is needed because`
	`687`	`+ * triggers expect to use that context as workspace. It's a bit ugly`
	`688`	`+ * to do this below the top level of the plan, however. We might need`
	`689`	`+ * to rethink this later.`
	`690`	`+ */`
	`691`	`+ ResetPerTupleExprContext(estate);`
	`692`	`+`
`685`	`693`	`planSlot = ExecProcNode(subplanstate);`
`686`	`694`
`687`	`695`	`if (TupIsNull(planSlot))`