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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-03-06 22:15:05 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-03-06 22:15:05 +0000 |
| commit | 849074f9ae422c64501bb1d53ef840de870bf65c (patch) | |
| tree | 9ac33ca6df68410da184659a4b0ca67f7bdf8bef /src/backend/utils/adt/selfuncs.c | |
| parent | 31b6d840f6fdbf3d272e7bf8ec0461742edcdd46 (diff) | |
| download | postgresql-849074f9ae422c64501bb1d53ef840de870bf65c.tar.gz postgresql-849074f9ae422c64501bb1d53ef840de870bf65c.zip | |
Revise hash join code so that we can increase the number of batches
on-the-fly, and thereby avoid blowing out memory when the planner has
underestimated the hash table size. Hash join will now obey the
work_mem limit with some faithfulness. Per my recent proposal
(hash aggregate part isn't done yet though).
Diffstat (limited to 'src/backend/utils/adt/selfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/selfuncs.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index b4536710eb0..c63eff09cdd 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -15,7 +15,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.171 2005/02/01 23:07:58 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.172 2005/03/06 22:15:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -2154,7 +2154,7 @@ estimate_num_groups(Query *root, List *groupExprs, double input_rows) * inner rel is well-dispersed (or the alternatives seem much worse). */ Selectivity -estimate_hash_bucketsize(Query *root, Node *hashkey, int nbuckets) +estimate_hash_bucketsize(Query *root, Node *hashkey, double nbuckets) { VariableStatData vardata; double estfract, @@ -2212,8 +2212,8 @@ estimate_hash_bucketsize(Query *root, Node *hashkey, int nbuckets) * the number of buckets is less than the expected number of distinct * values; otherwise it is 1/ndistinct. */ - if (ndistinct > (double) nbuckets) - estfract = 1.0 / (double) nbuckets; + if (ndistinct > nbuckets) + estfract = 1.0 / nbuckets; else estfract = 1.0 / ndistinct; |