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Currently,only the first column of multi-column indices

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is used to find start scan position of Indexscan-s.

To speed up finding scan start position,I have changed
_bt_first() to use as many keys as possible.

I'll attach the patch here.

Regards.

Hiroshi Inoue
This commit is contained in:
Bruce Momjian
1999-09-27 18:20:21 +00:00
parent 62045e67eb
commit 7b2a8e4e56
2 changed files with 92 additions and 48 deletions
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10
src/backend/access/nbtree/nbtutils.c
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@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtutils.c,v 1.32 1999/07/17 20:16:43 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtutils.c,v 1.33 1999/09/27 18:20:21 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -101,6 +101,7 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
uint16 numberOfKeys = so->numberOfKeys;
uint16 new_numberOfKeys = 0;
AttrNumber attno = 1;
bool equalStrategyEnd, underEqualStrategy;
if (numberOfKeys < 1)
return;
@@ -136,6 +137,8 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
for (j = 0; j <= BTMaxStrategyNumber; j++)
init[j] = 0;
equalStrategyEnd = false;
underEqualStrategy = true;
/* check each key passed in */
for (i = 0;;)
{
@@ -150,6 +153,7 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
if (cur->sk_attno != attno + 1 && i < numberOfKeys)
elog(ERROR, "_bt_orderkeys: key(s) for attribute %d missed", attno + 1);
underEqualStrategy = (!equalStrategyEnd);
/*
* If = has been specified, no other key will be used. In case
* of key < 2 && key == 1 and so on we have to set qual_ok to
@@ -175,6 +179,8 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
init[BTGreaterEqualStrategyNumber - 1] = 0;
init[BTGreaterStrategyNumber - 1] = 0;
}
else
equalStrategyEnd = true;
/* only one of <, <= */
if (init[BTLessStrategyNumber - 1]
@@ -223,7 +229,7 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
if (init[j])
key[new_numberOfKeys++] = xform[j];
if (attno == 1)
if (underEqualStrategy)
so->numberOfFirstKeys = new_numberOfKeys;
if (i == numberOfKeys)