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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2007-05-22 01:40:53 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2007-05-22 01:40:53 +0000 |
| commit | 9ccf784833d6ff0a1d89a8eb68094767cc1c1396 (patch) | |
| tree | 7861269c3d3e4875f43aa42854dfd0562ed64c50 /src/backend/nodes/outfuncs.c | |
| parent | 3c49269b90c2ef4ef69c40e15e164b787bbb583a (diff) | |
| download | postgresql-9ccf784833d6ff0a1d89a8eb68094767cc1c1396.tar.gz postgresql-9ccf784833d6ff0a1d89a8eb68094767cc1c1396.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 841db47aebc..19a888bdb8c 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 1.261.2.1 2005/11/14 23:54:34 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.261.2.2 2007/05/22 01:40:52 tgl Exp $ * * NOTES * Every node type that can appear in stored rules' parsetrees *must* @@ -1262,7 +1262,8 @@ _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 |