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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2007-05-22 01:40:33 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2007-05-22 01:40:33 +0000 |
| commit | d7153c5fadca610248775ef9c22ede85f08fd26a (patch) | |
| tree | 989a2483def7d8b8805353a8341a4607c54aec29 /src/backend/nodes/outfuncs.c | |
| parent | 2415ad983174164ff30ce487c0e6b4b53321b83a (diff) | |
| download | postgresql-d7153c5fadca610248775ef9c22ede85f08fd26a.tar.gz postgresql-d7153c5fadca610248775ef9c22ede85f08fd26a.zip | |
Fix best_inner_indexscan to return both the cheapest-total-cost and
cheapest-startup-cost innerjoin indexscans, and make joinpath.c consider
both of these (when different) as the inside of a nestloop join. The
original design was based on the assumption that indexscan paths always
have negligible startup cost, and so total cost is the only important
figure of merit; an assumption that's obviously broken by bitmap
indexscans. This oversight could lead to choosing poor plans in cases
where fast-start behavior is more important than total cost, such as
LIMIT and IN queries. 8.1-vintage brain fade exposed by an example from
Chuck D.
Diffstat (limited to 'src/backend/nodes/outfuncs.c')
| -rw-r--r-- | src/backend/nodes/outfuncs.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 58d8ee620bc..4bd923a38bc 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.306 2007/04/27 22:05:47 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.307 2007/05/22 01:40:33 tgl Exp $ * * NOTES * Every node type that can appear in stored rules' parsetrees *must* @@ -1440,7 +1440,8 @@ _outInnerIndexscanInfo(StringInfo str, InnerIndexscanInfo *node) WRITE_NODE_TYPE("INNERINDEXSCANINFO"); WRITE_BITMAPSET_FIELD(other_relids); WRITE_BOOL_FIELD(isouterjoin); - WRITE_NODE_FIELD(best_innerpath); + WRITE_NODE_FIELD(cheapest_startup_innerpath); + WRITE_NODE_FIELD(cheapest_total_innerpath); } static void |