diff options
Diffstat (limited to 'src/backend/executor/nodeAgg.c')
| -rw-r--r-- | src/backend/executor/nodeAgg.c | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c index 759ffeed2e6..0b02fd32107 100644 --- a/src/backend/executor/nodeAgg.c +++ b/src/backend/executor/nodeAgg.c @@ -402,12 +402,12 @@ static void find_cols(AggState *aggstate, Bitmapset **aggregated, Bitmapset **unaggregated); static bool find_cols_walker(Node *node, FindColsContext *context); static void build_hash_tables(AggState *aggstate); -static void build_hash_table(AggState *aggstate, int setno, long nbuckets); +static void build_hash_table(AggState *aggstate, int setno, double nbuckets); static void hashagg_recompile_expressions(AggState *aggstate, bool minslot, bool nullcheck); static void hash_create_memory(AggState *aggstate); -static long hash_choose_num_buckets(double hashentrysize, - long ngroups, Size memory); +static double hash_choose_num_buckets(double hashentrysize, + double ngroups, Size memory); static int hash_choose_num_partitions(double input_groups, double hashentrysize, int used_bits, @@ -1469,7 +1469,7 @@ build_hash_tables(AggState *aggstate) for (setno = 0; setno < aggstate->num_hashes; ++setno) { AggStatePerHash perhash = &aggstate->perhash[setno]; - long nbuckets; + double nbuckets; Size memory; if (perhash->hashtable != NULL) @@ -1478,8 +1478,6 @@ build_hash_tables(AggState *aggstate) continue; } - Assert(perhash->aggnode->numGroups > 0); - memory = aggstate->hash_mem_limit / aggstate->num_hashes; /* choose reasonable number of buckets per hashtable */ @@ -1505,7 +1503,7 @@ build_hash_tables(AggState *aggstate) * Build a single hashtable for this grouping set. */ static void -build_hash_table(AggState *aggstate, int setno, long nbuckets) +build_hash_table(AggState *aggstate, int setno, double nbuckets) { AggStatePerHash perhash = &aggstate->perhash[setno]; MemoryContext metacxt = aggstate->hash_metacxt; @@ -2053,11 +2051,11 @@ hash_create_memory(AggState *aggstate) /* * Choose a reasonable number of buckets for the initial hash table size. */ -static long -hash_choose_num_buckets(double hashentrysize, long ngroups, Size memory) +static double +hash_choose_num_buckets(double hashentrysize, double ngroups, Size memory) { - long max_nbuckets; - long nbuckets = ngroups; + double max_nbuckets; + double nbuckets = ngroups; max_nbuckets = memory / hashentrysize; @@ -2065,12 +2063,16 @@ hash_choose_num_buckets(double hashentrysize, long ngroups, Size memory) * Underestimating is better than overestimating. Too many buckets crowd * out space for group keys and transition state values. */ - max_nbuckets >>= 1; + max_nbuckets /= 2; if (nbuckets > max_nbuckets) nbuckets = max_nbuckets; - return Max(nbuckets, 1); + /* + * BuildTupleHashTable will clamp any obviously-insane result, so we don't + * need to be too careful here. + */ + return nbuckets; } /* @@ -3686,7 +3688,7 @@ ExecInitAgg(Agg *node, EState *estate, int eflags) if (use_hashing) { Plan *outerplan = outerPlan(node); - uint64 totalGroups = 0; + double totalGroups = 0; aggstate->hash_spill_rslot = ExecInitExtraTupleSlot(estate, scanDesc, &TTSOpsMinimalTuple); |