diff options
| author | Tomas Vondra | 2020-05-31 12:43:13 +0000 |
|---|---|---|
| committer | Tomas Vondra | 2020-05-31 12:43:13 +0000 |
| commit | 4cad2534da6d17067d98cf04be2dfc1bda8f2cd0 (patch) | |
| tree | 5b27dc496791ec122500851a35f3f63d46147828 /contrib/postgres_fdw | |
| parent | 9b60c4b979bce060495e2b05ba01d1cc6bffdd2d (diff) | |
Use CP_SMALL_TLIST for hash aggregate
Commit 1f39bce021 added disk-based hash aggregation, which may spill
incoming tuples to disk. It however did not request projection to make
the tuples as narrow as possible, which may mean having to spill much
more data than necessary (increasing I/O, pushing other stuff from page
cache, etc.).
This adds CP_SMALL_TLIST in places that may use hash aggregation - we do
that only for AGG_HASHED. It's unnecessary for AGG_SORTED, because that
either uses explicit Sort (which already does projection) or pre-sorted
input (which does not need spilling to disk).
Author: Tomas Vondra
Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/20200519151202.u2p2gpiawoaznsv2%40development
Diffstat (limited to 'contrib/postgres_fdw')
| -rw-r--r-- | contrib/postgres_fdw/expected/postgres_fdw.out | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out index 90db550b921..82fc1290ef2 100644 --- a/contrib/postgres_fdw/expected/postgres_fdw.out +++ b/contrib/postgres_fdw/expected/postgres_fdw.out @@ -2715,7 +2715,7 @@ select sum(c1) from ft1 group by c2 having avg(c1 * (random() <= 1)::int) > 100 Group Key: ft1.c2 Filter: (avg((ft1.c1 * ((random() <= '1'::double precision))::integer)) > '100'::numeric) -> Foreign Scan on public.ft1 - Output: c1, c2 + Output: c2, c1 Remote SQL: SELECT "C 1", c2 FROM "S 1"."T 1" (10 rows) @@ -2964,7 +2964,7 @@ select sum(c1) filter (where (c1 / c1) * random() <= 1) from ft1 group by c2 ord Output: sum(c1) FILTER (WHERE ((((c1 / c1))::double precision * random()) <= '1'::double precision)), c2 Group Key: ft1.c2 -> Foreign Scan on public.ft1 - Output: c1, c2 + Output: c2, c1 Remote SQL: SELECT "C 1", c2 FROM "S 1"."T 1" (9 rows) |