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| author | Bruce Momjian <bruce@momjian.us> | 1999-08-09 06:20:27 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 1999-08-09 06:20:27 +0000 |
| commit | 158fd5f1c4ab70f6db388e2bc7f4467b63d85457 (patch) | |
| tree | 7981105018fe9d0af5fb83f1ce367b570786c3ce /src/backend/executor | |
| parent | 5efe31214a6dff5c8fa06568d727bbf1f3e04a03 (diff) | |
| download | postgresql-158fd5f1c4ab70f6db388e2bc7f4467b63d85457.tar.gz postgresql-158fd5f1c4ab70f6db388e2bc7f4467b63d85457.zip | |
> > 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
Diffstat (limited to 'src/backend/executor')
| -rw-r--r-- | src/backend/executor/nodeIndexscan.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c index 0a35cf2cf8c..7be2f1b8c99 100644 --- a/src/backend/executor/nodeIndexscan.c +++ b/src/backend/executor/nodeIndexscan.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.40 1999/07/16 04:58:50 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/nodeIndexscan.c,v 1.41 1999/08/09 06:20:22 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -99,6 +99,13 @@ IndexNext(IndexScan *node) */ estate = node->scan.plan.state; direction = estate->es_direction; + if (ScanDirectionIsBackward(node->indxorderdir)) + { + if (ScanDirectionIsForward(direction)) + direction = BackwardScanDirection; + else if (ScanDirectionIsBackward(direction)) + direction = ForwardScanDirection; + } snapshot = estate->es_snapshot; scanstate = node->scan.scanstate; indexstate = node->indxstate; @@ -316,6 +323,8 @@ ExecIndexReScan(IndexScan *node, ExprContext *exprCtxt, Plan *parent) indxqual = node->indxqual; numScanKeys = indexstate->iss_NumScanKeys; indexstate->iss_IndexPtr = -1; + if (ScanDirectionIsBackward(node->indxorderdir)) + indexstate->iss_IndexPtr = numIndices; /* If this is re-scanning of PlanQual ... */ if (estate->es_evTuple != NULL && @@ -966,6 +975,8 @@ ExecInitIndexScan(IndexScan *node, EState *estate, Plan *parent) } indexstate->iss_NumIndices = numIndices; + if (ScanDirectionIsBackward(node->indxorderdir)) + indexPtr = numIndices; indexstate->iss_IndexPtr = indexPtr; indexstate->iss_ScanKeys = scanKeys; indexstate->iss_NumScanKeys = numScanKeys; |