1414 *
1515 *
1616 * IDENTIFICATION
17- * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.125 2005/07/28 22 :27:00 tgl Exp $
17+ * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.126 2005/08/02 20 :27:45 tgl Exp $
1818 *
1919 *-------------------------------------------------------------------------
2020 */
2121#include "postgres.h"
2222
2323
2424#include "access/heapam.h"
25+ #include "catalog/namespace.h"
2526#include "catalog/pg_type.h"
2627#include "nodes/makefuncs.h"
2728#include "optimizer/clauses.h"
@@ -807,6 +808,16 @@ expand_inherited_rtentry(PlannerInfo *root, Index rti)
807808RangeTblEntry * childrte ;
808809Index childRTindex ;
809810
811+ /*
812+ * It is possible that the parent table has children that are
813+ * temp tables of other backends. We cannot safely access such
814+ * tables (because of buffering issues), and the best thing to do
815+ * seems to be to silently ignore them.
816+ */
817+ if (childOID != parentOID &&
818+ isOtherTempNamespace (get_rel_namespace (childOID )))
819+ continue ;
820+
810821/*
811822 * Build an RTE for the child, and attach to query's rangetable
812823 * list. We copy most fields of the parent's RTE, but replace
@@ -820,6 +831,17 @@ expand_inherited_rtentry(PlannerInfo *root, Index rti)
820831inhRTIs = lappend_int (inhRTIs ,childRTindex );
821832}
822833
834+ /*
835+ * If all the children were temp tables, pretend it's a non-inheritance
836+ * situation. The duplicate RTE we added for the parent table is harmless.
837+ */
838+ if (list_length (inhRTIs )< 2 )
839+ {
840+ /* Clear flag to save repeated tests if called again */
841+ rte -> inh = false;
842+ return NIL ;
843+ }
844+
823845/*
824846 * The executor will check the parent table's access permissions when
825847 * it examines the parent's inheritlist entry. There's no need to