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* Hack for non-functional btree npages estimation:

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* npages = index_pages * selectivity_of_1st_attr_clause(s)
This commit is contained in:
Vadim B. Mikheev 1997-04-24 16:07:14 +00:00
parent 72d271177c
commit 67712200f1
1 changed files with 34 additions and 7 deletions
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39
src/backend/optimizer/util/plancat.c
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@ -8,7 +8,7 @@
* *
* *
* IDENTIFICATION * 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; float64data npages, select;
float64 amopnpages, amopselect; float64 amopnpages, amopselect;
Oid relam; Oid relam;
bool nphack = false;
float64data fattr_select = 1.0;
indRel = SearchSysCacheTuple(RELOID, indRel = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(indexrelid), ObjectIdGetDatum(indexrelid),
@ -516,6 +518,15 @@ IndexSelectivity(Oid indexrelid,
indexrelid); indexrelid);
index = (IndexTupleForm)GETSTRUCT(indexTuple); 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; npages = 0.0;
select = 1.0; select = 1.0;
for (n = 0; n < nIndexKeys; ++n) { for (n = 0; n < nIndexKeys; ++n) {
@ -556,7 +567,10 @@ IndexSelectivity(Oid indexrelid,
elog(WARN, "IndexSelectivity: no amop %d %d", elog(WARN, "IndexSelectivity: no amop %d %d",
indclass, operatorObjectIds[n]); indclass, operatorObjectIds[n]);
amop = (Form_pg_amop)GETSTRUCT(amopTuple); amop = (Form_pg_amop)GETSTRUCT(amopTuple);
amopnpages = (float64) fmgr(amop->amopnpages,
if ( !nphack )
{
amopnpages = (float64) fmgr(amop->amopnpages,
(char *) operatorObjectIds[n], (char *) operatorObjectIds[n],
(char *) indrelid, (char *) indrelid,
(char *) varAttributeNumbers[n], (char *) varAttributeNumbers[n],
@ -573,7 +587,8 @@ IndexSelectivity(Oid indexrelid,
if ((i = npages) < npages) /* ceil(npages)? */ if ((i = npages) < npages) /* ceil(npages)? */
npages += 1.0; npages += 1.0;
#endif #endif
npages += PointerIsValid(amopnpages) ? *amopnpages : 0.0; npages += PointerIsValid(amopnpages) ? *amopnpages : 0.0;
}
amopselect = (float64) fmgr(amop->amopselect, amopselect = (float64) fmgr(amop->amopselect,
(char *) operatorObjectIds[n], (char *) operatorObjectIds[n],
@ -583,15 +598,27 @@ IndexSelectivity(Oid indexrelid,
(char *) constFlags[n], (char *) constFlags[n],
(char *) nIndexKeys, (char *) nIndexKeys,
(char *) indexrelid); (char *) indexrelid);
if ( nphack && varAttributeNumbers[n] == index->indkey[0] )
fattr_select *= PointerIsValid(amopselect) ? *amopselect : 1.0;
select *= PointerIsValid(amopselect) ? *amopselect : 1.0; select *= PointerIsValid(amopselect) ? *amopselect : 1.0;
} }
/* /*
* Estimation of npages below is hack of course, but it's * Estimation of npages below is hack of course, but it's
* better than it was before. - vadim 04/09/97 * better than it was before. - vadim 04/09/97
*/ */
if ( nIndexKeys > 1 ) if ( nphack )
npages = npages / (1.0 + nIndexKeys); {
*idxPages = ceil ((double)(npages/nIndexKeys)); 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; *idxSelec = select;
} }