From 67712200f1148ff0a3fb807c74d12859a4e6d898 Mon Sep 17 00:00:00 2001
From: "Vadim B. Mikheev" <vadim4o@yahoo.com>
Date: Thu, 24 Apr 1997 16:07:14 +0000
Subject: [PATCH] * Hack for non-functional btree npages estimation:
* npages = index_pages * selectivity_of_1st_attr_clause(s)
---
src/backend/optimizer/util/plancat.c | 41 +++++++++++++++++++++++-----
1 file changed, 34 insertions(+), 7 deletions(-)
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index eda5830d2cf..abe764aa4e0 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.5 1997/04/09 01:52:04 vadim Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.6 1997/04/24 16:07:14 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@@ -499,6 +499,8 @@ IndexSelectivity(Oid indexrelid,
float64data npages, select;
float64 amopnpages, amopselect;
Oid relam;
+ bool nphack = false;
+ float64data fattr_select = 1.0;
indRel = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(indexrelid),
@@ -515,6 +517,15 @@ IndexSelectivity(Oid indexrelid,
elog(WARN, "IndexSelectivity: index %d not found",
indexrelid);
index = (IndexTupleForm)GETSTRUCT(indexTuple);
+
+ /*
+ * Hack for non-functional btree npages estimation:
+ * npages = index_pages * selectivity_of_1st_attr_clause(s)
+ * - vadim 04/24/97
+ */
+ if ( relam == BTREE_AM_OID &&
+ varAttributeNumbers[0] != InvalidAttrNumber )
+ nphack = true;
npages = 0.0;
select = 1.0;
@@ -556,7 +567,10 @@ IndexSelectivity(Oid indexrelid,
elog(WARN, "IndexSelectivity: no amop %d %d",
indclass, operatorObjectIds[n]);
amop = (Form_pg_amop)GETSTRUCT(amopTuple);
- amopnpages = (float64) fmgr(amop->amopnpages,
+
+ if ( !nphack )
+ {
+ amopnpages = (float64) fmgr(amop->amopnpages,
(char *) operatorObjectIds[n],
(char *) indrelid,
(char *) varAttributeNumbers[n],
@@ -573,8 +587,9 @@ IndexSelectivity(Oid indexrelid,
if ((i = npages) < npages) /* ceil(npages)? */
npages += 1.0;
#endif
- npages += PointerIsValid(amopnpages) ? *amopnpages : 0.0;
-
+ npages += PointerIsValid(amopnpages) ? *amopnpages : 0.0;
+ }
+
amopselect = (float64) fmgr(amop->amopselect,
(char *) operatorObjectIds[n],
(char *) indrelid,
@@ -583,15 +598,27 @@ IndexSelectivity(Oid indexrelid,
(char *) constFlags[n],
(char *) nIndexKeys,
(char *) indexrelid);
+
+ if ( nphack && varAttributeNumbers[n] == index->indkey[0] )
+ fattr_select *= PointerIsValid(amopselect) ? *amopselect : 1.0;
+
select *= PointerIsValid(amopselect) ? *amopselect : 1.0;
}
/*
* Estimation of npages below is hack of course, but it's
* better than it was before. - vadim 04/09/97
*/
- if ( nIndexKeys > 1 )
- npages = npages / (1.0 + nIndexKeys);
- *idxPages = ceil ((double)(npages/nIndexKeys));
+ if ( nphack )
+ {
+ npages = fattr_select * ((Form_pg_class)GETSTRUCT(indRel))->relpages;
+ *idxPages = ceil ((double)npages);
+ }
+ else
+ {
+ if ( nIndexKeys > 1 )
+ npages = npages / (1.0 + nIndexKeys);
+ *idxPages = ceil ((double)(npages/nIndexKeys));
+ }
*idxSelec = select;
}
--
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