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

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
index adfe97cefde9fad6c0b0def0fadbb4cb8eb7475f..969938130ec5bed7200f7f8c93abf0f1b85a2db1 100644 (file)
--- 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 1.7 2010/02/26 02:00:42 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeModifyTable.c,v 1.7.4.1 2010/08/18 21:52:32 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))