as inner plan of a mergejoin.
* 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 $
*
*-------------------------------------------------------------------------
*/
{
switch (nodeTag(node))
{
- case T_SeqScan:
+ case T_SeqScan:
ExecSeqMarkPos((SeqScan *) node);
break;
ExecIndexMarkPos((IndexScan *) node);
break;
+ case T_Material:
+ ExecMaterialMarkPos((Material *) node);
+ break;
+
case T_Sort:
ExecSortMarkPos((Sort *) node);
break;
{
switch (nodeTag(node))
{
- case T_SeqScan:
+ case T_SeqScan:
ExecSeqRestrPos((SeqScan *) node);
return;
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;
}
}
*
*
* 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 $
*
*-------------------------------------------------------------------------
*/
}
-#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;
}
/* ----------------------------------------------------------------
* ----------------------------------------------------------------
*/
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
*
*
* 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 $
*
*-------------------------------------------------------------------------
*/
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,
* 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 $
*
*-------------------------------------------------------------------------
*/
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 */
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