diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2000-04-18 05:43:02 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2000-04-18 05:43:02 +0000 |
| commit | 25442d8d2fd35389813062f523488821f4fc31d4 (patch) | |
| tree | d58f9ec0b5a7d3074c222008a9d58d5c35db5251 /src/backend/executor/nodeHash.c | |
| parent | 24864d048eec2c579346eb31a42c87be1c92644e (diff) | |
| download | postgresql-25442d8d2fd35389813062f523488821f4fc31d4.tar.gz postgresql-25442d8d2fd35389813062f523488821f4fc31d4.zip | |
Correct oversight in hashjoin cost estimation: nodeHash sizes its hash
table for an average of NTUP_PER_BUCKET tuples/bucket, but cost_hashjoin
was assuming a target load of one tuple/bucket. This was causing a
noticeable underestimate of hashjoin costs.
Diffstat (limited to 'src/backend/executor/nodeHash.c')
| -rw-r--r-- | src/backend/executor/nodeHash.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c index bee4a10f35d..1d841576fea 100644 --- a/src/backend/executor/nodeHash.c +++ b/src/backend/executor/nodeHash.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * - * $Id: nodeHash.c,v 1.44 2000/01/26 05:56:22 momjian Exp $ + * $Id: nodeHash.c,v 1.45 2000/04/18 05:43:01 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -221,7 +221,6 @@ ExecEndHash(Hash *node) * create a hashtable in shared memory for hashjoin. * ---------------------------------------------------------------- */ -#define NTUP_PER_BUCKET 10 #define FUDGE_FAC 2.0 HashJoinTable |