database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-28 23:42:10 +03:00
Code Activity

Refactor hash_agg_entry_size().

Browse Source 
Consolidate the calculations for hash table size estimation. This will
help with upcoming Hash Aggregation work that will add additional call
sites.
This commit is contained in:
Jeff Davis
2020-02-06 11:49:56 -08:00
parent c02fdc9223
commit 7d4395d0a1
4 changed files with 14 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
src/backend/optimizer/plan/planner.c
View File

@ -4867,13 +4867,8 @@ create_distinct_paths(PlannerInfo *root,
allow_hash = false; /* policy-based decision not to hash */
else
{
Size hashentrysize;
/* Estimate per-hash-entry space at tuple width... */
hashentrysize = MAXALIGN(cheapest_input_path->pathtarget->width) +
MAXALIGN(SizeofMinimalTupleHeader);
/* plus the per-hash-entry overhead */
hashentrysize += hash_agg_entry_size(0);
Size hashentrysize = hash_agg_entry_size(
0, cheapest_input_path->pathtarget->width, 0);
/* Allow hashing only if hashtable is predicted to fit in work_mem */
allow_hash = (hashentrysize * numDistinctRows <= work_mem * 1024L);