Back-patch fix for bogus plans involving non-mark/restorable plan

as inner plan of a mergejoin.

diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c
index 579465bf0b8916d11842e8c611319e602ebf709d..376eeef8b5dac1f606c59705792b02d3ce31132c 100644 (file)
--- a/src/backend/executor/execAmi.c
+++ b/src/backend/executor/execAmi.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *     $Id: execAmi.c,v 1.46 2000/04/12 17:15:07 momjian Exp $
+ *     $Id: execAmi.c,v 1.46.2.1 2000/09/08 02:11:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -424,7 +424,7 @@ ExecMarkPos(Plan *node)
 {
        switch (nodeTag(node))
        {
-                       case T_SeqScan:
+               case T_SeqScan:
                        ExecSeqMarkPos((SeqScan *) node);
                        break;
 
@@ -432,6 +432,10 @@ ExecMarkPos(Plan *node)
                        ExecIndexMarkPos((IndexScan *) node);
                        break;
 
+               case T_Material:
+                       ExecMaterialMarkPos((Material *) node);
+                       break;
+
                case T_Sort:
                        ExecSortMarkPos((Sort *) node);
                        break;
@@ -458,7 +462,7 @@ ExecRestrPos(Plan *node)
 {
        switch (nodeTag(node))
        {
-                       case T_SeqScan:
+               case T_SeqScan:
                        ExecSeqRestrPos((SeqScan *) node);
                        return;
 
@@ -466,12 +470,16 @@ ExecRestrPos(Plan *node)
                        ExecIndexRestrPos((IndexScan *) node);
                        return;
 
+               case T_Material:
+                       ExecMaterialRestrPos((Material *) node);
+                       break;
+
                case T_Sort:
                        ExecSortRestrPos((Sort *) node);
                        return;
 
                default:
-                       elog(DEBUG, "ExecRestrPos: node type %u not supported", nodeTag(node));
+                       elog(ERROR, "ExecRestrPos: node type %u not supported", nodeTag(node));
                        return;
        }
 }

diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c
index 4348f89ccc9746b4a8c0b845fa3c31d001c1fc8e..4f67892682b6b8d166951563c0762744b6e446f7 100644 (file)
--- 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 1.30 2000/03/02 04:06:39 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/executor/nodeMaterial.c,v 1.30.2.1 2000/09/08 02:11:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -352,35 +352,30 @@ ExecMaterialReScan(Material *node, ExprContext *exprCtxt, Plan *parent)
 
 }
 
-#ifdef NOT_USED                                        /* not used */
 /* ----------------------------------------------------------------
  *             ExecMaterialMarkPos
  * ----------------------------------------------------------------
  */
-List                                                   /* nothing of interest */
-ExecMaterialMarkPos(Material node)
+void
+ExecMaterialMarkPos(Material *node)
 {
-       MaterialState matstate;
+       MaterialState *matstate;
        HeapScanDesc scan;
 
        /* ----------------
-        *      if we haven't materialized yet, just return NIL.
+        *      if we haven't materialized yet, just return.
         * ----------------
         */
-       matstate = get_matstate(node);
-       if (get_mat_Flag(matstate) == false)
-               return NIL;
+       matstate = node->matstate;
+       if (matstate->mat_Flag == false)
+               return;
 
        /* ----------------
-        *      XXX access methods don't return positions yet so
-        *              for now we return NIL.  It's possible that
-        *              they will never return positions for all I know -cim 10/16/89
+        *      mark the scan position
         * ----------------
         */
-       scan = get_css_currentScanDesc((CommonScanState) matstate);
+       scan = matstate->csstate.css_currentScanDesc;
        heap_markpos(scan);
-
-       return NIL;
 }
 
 /* ----------------------------------------------------------------
@@ -388,25 +383,23 @@ ExecMaterialMarkPos(Material node)
  * ----------------------------------------------------------------
  */
 void
-ExecMaterialRestrPos(Material node)
+ExecMaterialRestrPos(Material *node)
 {
-       MaterialState matstate;
+       MaterialState *matstate;
        HeapScanDesc scan;
 
        /* ----------------
         *      if we haven't materialized yet, just return.
         * ----------------
         */
-       matstate = get_matstate(node);
-       if (get_mat_Flag(matstate) == false)
+       matstate = node->matstate;
+       if (matstate->mat_Flag == false)
                return;
 
        /* ----------------
         *      restore the scan to the previously marked position
         * ----------------
         */
-       scan = get_css_currentScanDesc((CommonScanState) matstate);
+       scan = matstate->csstate.css_currentScanDesc;
        heap_restrpos(scan);
 }
-
-#endif

diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index 4109ab25364625477911ee355f2b55101af8d220..7d4a34b4f4b48c331900dd4afb7e89284a8363e2 100644 (file)
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.90 2000/05/23 16:56:36 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.90.2.1 2000/09/08 02:11:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -639,6 +639,44 @@ create_mergejoin_node(MergePath *best_path,
                                                                                  best_path->innersortkeys,
                                                                                  inner_node);
 
+       /*
+        * The executor requires the inner side of a mergejoin to support "mark"
+        * and "restore" operations.  Not all plan types do, so we must be careful
+        * not to generate an invalid plan.  If necessary, an invalid inner plan
+        * can be handled by inserting a Materialize node.
+        *
+        * Since the inner side must be ordered, and only Sorts and IndexScans can
+        * create order to begin with, you might think there's no problem --- but
+        * you'd be wrong.  Nestloop and merge joins can *preserve* the order of
+        * their inputs, so they can be selected as the input of a mergejoin,
+        * and that won't work in the present executor.
+        *
+        * Doing this here is a bit of a kluge since the cost of the Materialize
+        * wasn't taken into account in our earlier decisions.  But Materialize
+        * is hard to estimate a cost for, and the above consideration shows that
+        * this is a rare case anyway, so this seems an acceptable way to proceed.
+        *
+        * This check must agree with ExecMarkPos/ExecRestrPos in
+        * executor/execAmi.c!
+        */
+       switch (nodeTag(inner_node))
+       {
+               case T_SeqScan:
+               case T_IndexScan:
+               case T_Material:
+               case T_Sort:
+                       /* OK, these inner plans support mark/restore */
+                       break;
+
+               default:
+                       /* Ooops, need to materialize the inner plan */
+                       inner_node = (Plan *) make_material(inner_tlist,
+                                                                                               _NONAME_RELATION_ID_,
+                                                                                               inner_node,
+                                                                                               0);
+                       break;
+       }
+
        join_node = make_mergejoin(tlist,
                                                           qpqual,
                                                           mergeclauses,

diff --git a/src/include/executor/nodeMaterial.h b/src/include/executor/nodeMaterial.h
index 1daf0bd0afeb42a481e49244b1f25f9a67b562f2..0696cba155a33d6fbd3df496883113f13fd6dc87 100644 (file)
--- a/src/include/executor/nodeMaterial.h
+++ b/src/include/executor/nodeMaterial.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodeMaterial.h,v 1.12 2000/01/26 05:58:05 momjian Exp $
+ * $Id: nodeMaterial.h,v 1.12.2.1 2000/09/08 02:11:31 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,11 +20,8 @@ extern TupleTableSlot *ExecMaterial(Material *node);
 extern bool ExecInitMaterial(Material *node, EState *estate, Plan *parent);
 extern int     ExecCountSlotsMaterial(Material *node);
 extern void ExecEndMaterial(Material *node);
-extern void ExecMaterialReScan(Material *node, ExprContext *exprCtxt, Plan *parent);
-
-#ifdef NOT_USED
-extern List ExecMaterialMarkPos(Material *node);
+extern void ExecMaterialMarkPos(Material *node);
 extern void ExecMaterialRestrPos(Material *node);
+extern void ExecMaterialReScan(Material *node, ExprContext *exprCtxt, Plan *parent);
 
-#endif
 #endif  /* NODEMATERIAL_H */