> > Prevent sorting if result is already sorted
> > > > was implemented by Jan Wieck. > > His work is for ascending order cases. > > > > Here is a patch to prevent sorting also in descending > > order cases. > > Because I had already changed _bt_first() to position > > backward correctly before v6.5,this patch would work. > > Hiroshi Inoue Inoue@tpf.co.jp
This commit is contained in:
Bruce Momjian
parent
5efe31214a
commit
158fd5f1c4
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@ -4,7 +4,7 @@
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*
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* Copyright (c) 1994-5, Regents of the University of California
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*
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* $Id: explain.c,v 1.43 1999/07/17 20:16:52 momjian Exp $
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* $Id: explain.c,v 1.44 1999/08/09 06:20:21 momjian Exp $
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*
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*/
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@ -200,6 +200,8 @@ explain_outNode(StringInfo str, Plan *plan, int indent, ExplainState *es)
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switch (nodeTag(plan))
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{
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case T_IndexScan:
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if (ScanDirectionIsBackward(((IndexScan *)plan)->indxorderdir))
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appendStringInfo(str, " Backward");
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appendStringInfo(str, " using ");
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i = 0;
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foreach(l, ((IndexScan *) plan)->indxid)
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.40 1999/07/16 04:58:50 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.41 1999/08/09 06:20:22 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -99,6 +99,13 @@ IndexNext(IndexScan *node)
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*/
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estate = node->scan.plan.state;
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direction = estate->es_direction;
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if (ScanDirectionIsBackward(node->indxorderdir))
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{
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if (ScanDirectionIsForward(direction))
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direction = BackwardScanDirection;
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else if (ScanDirectionIsBackward(direction))
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direction = ForwardScanDirection;
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}
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snapshot = estate->es_snapshot;
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scanstate = node->scan.scanstate;
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indexstate = node->indxstate;
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@ -316,6 +323,8 @@ ExecIndexReScan(IndexScan *node, ExprContext *exprCtxt, Plan *parent)
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indxqual = node->indxqual;
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numScanKeys = indexstate->iss_NumScanKeys;
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indexstate->iss_IndexPtr = -1;
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if (ScanDirectionIsBackward(node->indxorderdir))
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indexstate->iss_IndexPtr = numIndices;
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/* If this is re-scanning of PlanQual ... */
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if (estate->es_evTuple != NULL &&
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@ -966,6 +975,8 @@ ExecInitIndexScan(IndexScan *node, EState *estate, Plan *parent)
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}
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indexstate->iss_NumIndices = numIndices;
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if (ScanDirectionIsBackward(node->indxorderdir))
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indexPtr = numIndices;
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indexstate->iss_IndexPtr = indexPtr;
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indexstate->iss_ScanKeys = scanKeys;
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indexstate->iss_NumScanKeys = numScanKeys;
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.89 1999/07/27 03:51:07 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.90 1999/08/09 06:20:23 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -238,6 +238,7 @@ _copyIndexScan(IndexScan *from)
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newnode->indxid = listCopy(from->indxid);
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Node_Copy(from, newnode, indxqual);
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Node_Copy(from, newnode, indxqualorig);
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newnode->indxorderdir = from->indxorderdir;
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return newnode;
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}
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.45 1999/07/29 02:45:36 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.46 1999/08/09 06:20:24 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -437,6 +437,9 @@ _equalIndexScan(IndexScan *a, IndexScan *b)
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if (a->scan.scanrelid != b->scan.scanrelid)
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return false;
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if (a->indxorderdir != b->indxorderdir)
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return false;
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if (!equali(a->indxid, b->indxid))
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return false;
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return true;
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@ -5,7 +5,7 @@
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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* $Id: outfuncs.c,v 1.91 1999/07/24 23:21:07 tgl Exp $
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* $Id: outfuncs.c,v 1.92 1999/08/09 06:20:24 momjian Exp $
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*
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* NOTES
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* Every (plan) node in POSTGRES has an associated "out" routine which
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@ -445,6 +445,7 @@ _outIndexScan(StringInfo str, IndexScan *node)
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appendStringInfo(str, " :indxqualorig ");
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_outNode(str, node->indxqualorig);
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appendStringInfo(str, " :indxorderdir %d ", node->indxorderdir);
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}
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/*
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.70 1999/07/24 23:21:08 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.71 1999/08/09 06:20:24 momjian Exp $
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*
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* NOTES
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* Most of the read functions for plan nodes are tested. (In fact, they
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@ -532,6 +532,11 @@ _readIndexScan()
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token = lsptok(NULL, &length); /* eat :indxqualorig */
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local_node->indxqualorig = nodeRead(true); /* now read it */
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token = lsptok(NULL, &length); /* eat :indxorderdir */
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token = lsptok(NULL, &length); /* get indxorderdir */
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local_node->indxorderdir = atoi(token);
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return local_node;
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}
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.67 1999/08/09 01:01:42 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.68 1999/08/09 06:20:26 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -1024,6 +1024,7 @@ make_indexscan(List *qptlist,
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node->indxid = indxid;
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node->indxqual = indxqual;
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node->indxqualorig = indxqualorig;
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node->indxorderdir = NoMovementScanDirection;
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node->scan.scanstate = (CommonScanState *) NULL;
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return node;
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.61 1999/07/17 20:17:15 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.62 1999/08/09 06:20:26 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -39,7 +39,7 @@ static List *make_subplanTargetList(Query *parse, List *tlist,
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static Plan *make_groupplan(List *group_tlist, bool tuplePerGroup,
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List *groupClause, AttrNumber *grpColIdx,
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Plan *subplan);
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static bool need_sortplan(List *sortcls, Plan *plan);
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static ScanDirection get_dir_to_omit_sortplan(List *sortcls, Plan *plan);
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static Plan *make_sortplan(List *tlist, List *sortcls, Plan *plannode);
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/*****************************************************************************
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@ -303,8 +303,17 @@ union_planner(Query *parse)
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}
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else
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{
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if (parse->sortClause && need_sortplan(parse->sortClause, result_plan))
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return (make_sortplan(tlist, parse->sortClause, result_plan));
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if (parse->sortClause)
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{
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ScanDirection dir = get_dir_to_omit_sortplan(parse->sortClause, result_plan);
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if (ScanDirectionIsNoMovement(dir))
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return (make_sortplan(tlist, parse->sortClause, result_plan));
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else
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{
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((IndexScan *)result_plan)->indxorderdir = dir;
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return ((Plan *) result_plan);
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}
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}
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else
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return ((Plan *) result_plan);
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}
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@ -822,7 +831,7 @@ pg_checkretval(Oid rettype, List *queryTreeList)
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/* ----------
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* Support function for need_sortplan
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* Support function for get scan direction to omit sortplan
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* ----------
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*/
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static TargetEntry *
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@ -845,11 +854,13 @@ get_matching_tle(Plan *plan, Resdom *resdom)
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* Check if a user requested ORDER BY is already satisfied by
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* the choosen index scan.
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*
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* Returns TRUE if sort is required, FALSE if can be omitted.
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* Returns the direction of Index scan to omit sort,
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* if sort is required returns NoMovementScanDirection
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*
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* ----------
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*/
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static bool
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need_sortplan(List *sortcls, Plan *plan)
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static ScanDirection
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get_dir_to_omit_sortplan(List *sortcls, Plan *plan)
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{
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Relation indexRel;
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IndexScan *indexScan;
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@ -858,13 +869,15 @@ need_sortplan(List *sortcls, Plan *plan)
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HeapTuple htup;
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Form_pg_index index_tup;
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int key_no = 0;
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ScanDirection dir, nodir = NoMovementScanDirection;
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dir = nodir;
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/* ----------
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* Must be an IndexScan
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* ----------
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*/
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if (nodeTag(plan) != T_IndexScan)
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return TRUE;
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return nodir;
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indexScan = (IndexScan *) plan;
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@ -873,16 +886,16 @@ need_sortplan(List *sortcls, Plan *plan)
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* ----------
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*/
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if (plan->lefttree != NULL)
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return TRUE;
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return nodir;
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if (plan->righttree != NULL)
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return TRUE;
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return nodir;
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/* ----------
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* Must be a single index scan
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* ----------
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*/
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if (length(indexScan->indxid) != 1)
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return TRUE;
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return nodir;
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/* ----------
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* Indices can only have up to 8 attributes. So an ORDER BY using
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@ -890,7 +903,7 @@ need_sortplan(List *sortcls, Plan *plan)
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* ----------
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*/
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if (length(sortcls) > 8)
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return TRUE;
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return nodir;
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/* ----------
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* The choosen Index must be a btree
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@ -902,7 +915,7 @@ need_sortplan(List *sortcls, Plan *plan)
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if (strcmp(nameout(&(indexRel->rd_am->amname)), "btree") != 0)
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{
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heap_close(indexRel);
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return TRUE;
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return nodir;
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}
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heap_close(indexRel);
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@ -937,7 +950,7 @@ need_sortplan(List *sortcls, Plan *plan)
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* Could this happen?
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* ----------
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*/
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return TRUE;
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return nodir;
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}
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if (nodeTag(tle->expr) != T_Var)
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{
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@ -946,7 +959,7 @@ need_sortplan(List *sortcls, Plan *plan)
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* cannot be the indexed attribute
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* ----------
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*/
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return TRUE;
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return nodir;
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}
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var = (Var *) (tle->expr);
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@ -957,7 +970,7 @@ need_sortplan(List *sortcls, Plan *plan)
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* that of the index
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* ----------
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*/
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return TRUE;
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return nodir;
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}
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if (var->varattno != index_tup->indkey[key_no])
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@ -966,7 +979,7 @@ need_sortplan(List *sortcls, Plan *plan)
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* It isn't the indexed attribute.
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* ----------
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*/
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return TRUE;
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return nodir;
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}
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if (oprid(oper("<", resdom->restype, resdom->restype, FALSE)) != sortcl->opoid)
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@ -975,7 +988,19 @@ need_sortplan(List *sortcls, Plan *plan)
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* Sort order isn't in ascending order.
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* ----------
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*/
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return TRUE;
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if (ScanDirectionIsForward(dir))
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return nodir;
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dir = BackwardScanDirection;
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}
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else
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{
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/* ----------
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* Sort order is in ascending order.
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* ----------
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*/
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if (ScanDirectionIsBackward(dir))
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return nodir;
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dir = ForwardScanDirection;
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}
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key_no++;
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@ -985,5 +1010,5 @@ need_sortplan(List *sortcls, Plan *plan)
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* Index matches ORDER BY - sort not required
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* ----------
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*/
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return FALSE;
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return dir;
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}
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@ -6,7 +6,7 @@
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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* $Id: plannodes.h,v 1.28 1999/07/15 23:03:55 momjian Exp $
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* $Id: plannodes.h,v 1.29 1999/08/09 06:20:27 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -175,6 +175,7 @@ typedef struct IndexScan
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List *indxid;
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List *indxqual;
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List *indxqualorig;
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ScanDirection indxorderdir;
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IndexScanState *indxstate;
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} IndexScan;
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Loading…
Reference in New Issue