diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/executor/nodeHash.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c index eca5f1b34d0..b50cb231d19 100644 --- a/src/backend/executor/nodeHash.c +++ b/src/backend/executor/nodeHash.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.116 2008/01/01 19:45:49 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.116.2.1 2009/10/30 20:58:57 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -363,6 +363,7 @@ ExecChooseHashTableSize(double ntuples, int tupwidth, int tupsize; double inner_rel_bytes; long hash_table_bytes; + long max_pointers; int nbatch; int nbuckets; int i; @@ -389,8 +390,13 @@ ExecChooseHashTableSize(double ntuples, int tupwidth, /* * Set nbuckets to achieve an average bucket load of NTUP_PER_BUCKET when * memory is filled. Set nbatch to the smallest power of 2 that appears - * sufficient. + * sufficient. The Min() steps limit the results so that the pointer + * arrays we'll try to allocate do not exceed work_mem. */ + max_pointers = (work_mem * 1024L) / sizeof(void *); + /* also ensure we avoid integer overflow in nbatch and nbuckets */ + max_pointers = Min(max_pointers, INT_MAX / 2); + if (inner_rel_bytes > hash_table_bytes) { /* We'll need multiple batches */ @@ -399,11 +405,11 @@ ExecChooseHashTableSize(double ntuples, int tupwidth, int minbatch; lbuckets = (hash_table_bytes / tupsize) / NTUP_PER_BUCKET; - lbuckets = Min(lbuckets, INT_MAX / 2); + lbuckets = Min(lbuckets, max_pointers); nbuckets = (int) lbuckets; dbatch = ceil(inner_rel_bytes / hash_table_bytes); - dbatch = Min(dbatch, INT_MAX / 2); + dbatch = Min(dbatch, max_pointers); minbatch = (int) dbatch; nbatch = 2; while (nbatch < minbatch) @@ -415,7 +421,7 @@ ExecChooseHashTableSize(double ntuples, int tupwidth, double dbuckets; dbuckets = ceil(ntuples / NTUP_PER_BUCKET); - dbuckets = Min(dbuckets, INT_MAX / 2); + dbuckets = Min(dbuckets, max_pointers); nbuckets = (int) dbuckets; nbatch = 1; @@ -489,7 +495,7 @@ ExecHashIncreaseNumBatches(HashJoinTable hashtable) return; /* safety check to avoid overflow */ - if (oldnbatch > INT_MAX / 2) + if (oldnbatch > Min(INT_MAX / 2, MaxAllocSize / (sizeof(void *) * 2))) return; nbatch = oldnbatch * 2; |