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| 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/include/executor/nodeHash.h | |
| 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/include/executor/nodeHash.h')
| -rw-r--r-- | src/include/executor/nodeHash.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/include/executor/nodeHash.h b/src/include/executor/nodeHash.h index 0460368d8b1..b61ced7cdc1 100644 --- a/src/include/executor/nodeHash.h +++ b/src/include/executor/nodeHash.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: nodeHash.h,v 1.15 2000/01/26 05:58:05 momjian Exp $ + * $Id: nodeHash.h,v 1.16 2000/04/18 05:43:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -16,6 +16,9 @@ #include "nodes/plannodes.h" +/* NTUP_PER_BUCKET is exported because planner wants to see it */ +#define NTUP_PER_BUCKET 10 + extern TupleTableSlot *ExecHash(Hash *node); extern bool ExecInitHash(Hash *node, EState *estate, Plan *parent); extern int ExecCountSlotsHash(Hash *node); |