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Separate predicate-testing code out of indxpath.c, making it a module

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in its own right.  As proposed by Simon Riggs, but with some editorializing
of my own.
This commit is contained in:
Tom Lane
2005-06-10 22:25:37 +00:00
parent 111e29ef5e
commit 2f1210629c
7 changed files with 728 additions and 685 deletions
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13
src/backend/utils/adt/selfuncs.c
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@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.180 2005/06/05 22:32:57 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.181 2005/06/10 22:25:36 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -4221,12 +4221,11 @@ genericcostestimate(PlannerInfo *root,
* of partial redundancy (such as "x < 4" from the qual and "x < 5"
* from the predicate) will be recognized and handled correctly by
* clauselist_selectivity(). This assumption is somewhat fragile,
* since it depends on pred_test() and clauselist_selectivity() having
* similar capabilities, and there are certainly many cases where we
* will end up with a too-low selectivity estimate. This will bias
* the system in favor of using partial indexes where possible, which
* is not necessarily a bad thing. But it'd be nice to do better
* someday.
* since it depends on predicate_implied_by() and clauselist_selectivity()
* having similar capabilities, and there are certainly many cases where
* we will end up with a too-low selectivity estimate. This will bias the
* system in favor of using partial indexes where possible, which is not
* necessarily a bad thing. But it'd be nice to do better someday.
*
* Note that index->indpred and indexQuals are both in implicit-AND form,
* so ANDing them together just takes merging the lists. However,