Back-patch nodeMaterial to honor chgParam by recomputing its output.

diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c
index 4f67892682b6b8d166951563c0762744b6e446f7..bbe4fad4e5079a93e357c74b0f72c45b91caae65 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 1.30.2.1 2000/09/08 02:11:32 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/executor/nodeMaterial.c,v 1.30.2.2 2000/10/06 01:28:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -39,12 +39,6 @@
  *             calls to ExecMaterial return successive tuples from the temp
  *             relation.
  *
- *             Initial State:
- *
- *             ExecMaterial assumes the temporary relation has been
- *             created and opened by ExecInitMaterial during the prior
- *             InitPlan() phase.
- *
  * ----------------------------------------------------------------
  */
 TupleTableSlot *                               /* result tuple from subplan */
@@ -78,25 +72,54 @@ ExecMaterial(Material *node)
 
        if (matstate->mat_Flag == false)
        {
+               TupleDesc       tupType;
+
                /* ----------------
-                *      set all relations to be scanned in the forward direction
-                *      while creating the temporary relation.
+                *      get type information needed for ExecCreatR
                 * ----------------
                 */
-               estate->es_direction = ForwardScanDirection;
+               tupType = ExecGetScanType(&matstate->csstate);
+
+               /* ----------------
+                *      ExecCreatR wants its second argument to be an object id of
+                *      a relation in the range table or a _NONAME_RELATION_ID
+                *      indicating that the relation is not in the range table.
+                *
+                *      In the second case ExecCreatR creates a temp relation.
+                *      (currently this is the only case we support -cim 10/16/89)
+                * ----------------
+                */
+               /* ----------------
+                *      create the temporary relation
+                * ----------------
+                */
+               tempRelation = ExecCreatR(tupType, _NONAME_RELATION_ID_);
 
                /* ----------------
                 *       if we couldn't create the temp relation then
                 *       we print a warning and return NULL.
                 * ----------------
                 */
-               tempRelation = matstate->mat_TempRelation;
                if (tempRelation == NULL)
                {
                        elog(DEBUG, "ExecMaterial: temp relation is NULL! aborting...");
                        return NULL;
                }
 
+               /* ----------------
+                *      save the relation descriptor in the sortstate
+                * ----------------
+                */
+               matstate->mat_TempRelation = tempRelation;
+               matstate->csstate.css_currentRelation = NULL;
+
+               /* ----------------
+                *      set all relations to be scanned in the forward direction
+                *      while creating the temporary relation.
+                * ----------------
+                */
+               estate->es_direction = ForwardScanDirection;
+
                /* ----------------
                 *       retrieve tuples from the subplan and
                 *       insert them in the temporary relation
@@ -135,9 +158,6 @@ ExecMaterial(Material *node)
                matstate->csstate.css_currentRelation = currentRelation;
                matstate->csstate.css_currentScanDesc = currentScanDesc;
 
-               ExecAssignScanType(&matstate->csstate,
-                                                  RelationGetDescr(currentRelation));
-
                /* ----------------
                 *      finally set the sorted flag to true
                 * ----------------
@@ -178,10 +198,6 @@ ExecInitMaterial(Material *node, EState *estate, Plan *parent)
 {
        MaterialState *matstate;
        Plan       *outerPlan;
-       TupleDesc       tupType;
-       Relation        tempDesc;
-
-       /* int                                          len; */
 
        /* ----------------
         *      assign the node's execution state
@@ -225,12 +241,6 @@ ExecInitMaterial(Material *node, EState *estate, Plan *parent)
        outerPlan = outerPlan((Plan *) node);
        ExecInitNode(outerPlan, estate, (Plan *) node);
 
-       /* ----------------
-        *      initialize matstate information
-        * ----------------
-        */
-       matstate->mat_Flag = false;
-
        /* ----------------
         *      initialize tuple type.  no need to initialize projection
         *      info because this node doesn't do projections.
@@ -239,39 +249,6 @@ ExecInitMaterial(Material *node, EState *estate, Plan *parent)
        ExecAssignScanTypeFromOuterPlan((Plan *) node, &matstate->csstate);
        matstate->csstate.cstate.cs_ProjInfo = NULL;
 
-       /* ----------------
-        *      get type information needed for ExecCreatR
-        * ----------------
-        */
-       tupType = ExecGetScanType(&matstate->csstate);
-
-       /* ----------------
-        *      ExecCreatR wants its second argument to be an object id of
-        *      a relation in the range table or a _NONAME_RELATION_ID
-        *      indicating that the relation is not in the range table.
-        *
-        *      In the second case ExecCreatR creates a temp relation.
-        *      (currently this is the only case we support -cim 10/16/89)
-        * ----------------
-        */
-       /* ----------------
-        *      create the temporary relation
-        * ----------------
-        */
-       tempDesc = ExecCreatR(tupType, _NONAME_RELATION_ID_);
-
-       /* ----------------
-        *      save the relation descriptor in the sortstate
-        * ----------------
-        */
-       matstate->mat_TempRelation = tempDesc;
-       matstate->csstate.css_currentRelation = NULL;
-
-       /* ----------------
-        *      return relation oid of temporary relation in a list
-        *      (someday -- for now we return LispTrue... cim 10/12/89)
-        * ----------------
-        */
        return TRUE;
 }
 
@@ -343,13 +320,39 @@ ExecMaterialReScan(Material *node, ExprContext *exprCtxt, Plan *parent)
 {
        MaterialState *matstate = node->matstate;
 
+       /*
+        * If we haven't materialized yet, just return. If outerplan' chgParam is
+        * not NULL then it will be re-scanned by ExecProcNode, else - no
+        * reason to re-scan it at all.
+        */
        if (matstate->mat_Flag == false)
                return;
 
-       matstate->csstate.css_currentScanDesc = ExecReScanR(matstate->csstate.css_currentRelation,
-                                                                  matstate->csstate.css_currentScanDesc,
-                                                               node->plan.state->es_direction, 0, NULL);
-
+       /*
+        * If subnode is to be rescanned then we forget previous stored results;
+        * we have to re-read the subplan and re-store.
+        *
+        * Otherwise we can just rewind and rescan the stored output.
+        */
+       if (((Plan *) node)->lefttree->chgParam != NULL)
+       {
+               Relation        tempRelation = matstate->mat_TempRelation;
+
+               matstate->csstate.css_currentRelation = NULL;
+               ExecCloseR((Plan *) node);
+               ExecClearTuple(matstate->csstate.css_ScanTupleSlot);
+               if (tempRelation != NULL)
+                       heap_drop(tempRelation);
+               matstate->mat_TempRelation = NULL;
+               matstate->mat_Flag = false;
+       }
+       else
+       {
+               matstate->csstate.css_currentScanDesc =
+                       ExecReScanR(matstate->csstate.css_currentRelation,
+                                               matstate->csstate.css_currentScanDesc,
+                                               node->plan.state->es_direction, 0, NULL);
+       }
 }
 
 /* ----------------------------------------------------------------