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| author | Jeff Davis <jdavis@postgresql.org> | 2020-03-24 18:19:51 -0700 |
|---|---|---|
| committer | Jeff Davis <jdavis@postgresql.org> | 2020-03-24 18:30:04 -0700 |
| commit | dd8e19132acfbb28d579288a412ed6c0a5ea338b (patch) | |
| tree | 00f77cc5a56e95ff1ffb9043aae25859ca4e1563 /src | |
| parent | 3649133b147638f25933c93e3d4f6b920da50332 (diff) | |
| download | postgresql-dd8e19132acfbb28d579288a412ed6c0a5ea338b.tar.gz postgresql-dd8e19132acfbb28d579288a412ed6c0a5ea338b.zip | |
Consider disk-based hash aggregation to implement DISTINCT.
Correct oversight in 1f39bce0. If enable_hashagg_disk=true, we should
consider hash aggregation for DISTINCT when applicable.
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 5da05283822..b65abf6046d 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -4868,8 +4868,8 @@ create_distinct_paths(PlannerInfo *root, 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); + allow_hash = enable_hashagg_disk || + (hashentrysize * numDistinctRows <= work_mem * 1024L); } if (allow_hash && grouping_is_hashable(parse->distinctClause)) |