mirror of
https://github.com/timescale/timescaledb.git
synced 2025-05-17 02:53:51 +08:00
f1e103fab1
Previously, we would push DISTINCT ON down to the data nodes even when the pathkeys of the resulting paths on the data nodes were not compatible with the given DISTINCT ON columns. This commit disables pushdown when the sorting is not compatible. Fixes #3784
61 lines
2.3 KiB
SQL
61 lines
2.3 KiB
SQL
-- This file and its contents are licensed under the Timescale License.
|
|
-- Please see the included NOTICE for copyright information and
|
|
-- LICENSE-TIMESCALE for a copy of the license.
|
|
|
|
-- Test DISTINCT ON pushdown.
|
|
|
|
|
|
-- The case with LIMIT serves as a reference.
|
|
select ts, id from distinct_on_hypertable order by id, ts desc limit 1;
|
|
select ts, id from distinct_on_distributed order by id, ts desc limit 1;
|
|
|
|
|
|
-- DISTINCT ON should match the above LIMIT for the first id.
|
|
select distinct on (id) ts, id from distinct_on_hypertable order by id, ts desc;
|
|
|
|
select distinct on (id) ts, id from distinct_on_distributed order by id, ts desc;
|
|
|
|
explain (costs off, verbose)
|
|
select distinct on (id) ts, id from distinct_on_distributed order by id, ts desc;
|
|
|
|
|
|
-- A case where we have a filter on the DISTINCT ON column.
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0', '1') order by id, ts desc;
|
|
|
|
explain (costs off, verbose)
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0', '1') order by id, ts desc;
|
|
|
|
|
|
-- A somewhat dumb case where the DISTINCT ON column is deduced to be constant
|
|
-- and not added to pathkeys.
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0') order by id, ts desc;
|
|
|
|
explain (costs off, verbose)
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0') order by id, ts desc;
|
|
|
|
|
|
-- All above but with disabled local sort, to try to force more interesting plans where the sort
|
|
-- is pushed down.
|
|
set enable_sort = 0;
|
|
|
|
select ts, id from distinct_on_distributed order by id, ts desc limit 1;
|
|
|
|
explain (costs off, verbose)
|
|
select ts, id from distinct_on_distributed order by id, ts desc limit 1;
|
|
|
|
select distinct on (id) ts, id from distinct_on_distributed order by id, ts desc;
|
|
|
|
explain (costs off, verbose)
|
|
select distinct on (id) ts, id from distinct_on_distributed order by id, ts desc;
|
|
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0', '1') order by id, ts desc;
|
|
|
|
explain (costs off, verbose)
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0', '1') order by id, ts desc;
|
|
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0') order by id, ts desc;
|
|
|
|
explain (costs off, verbose)
|
|
select distinct on (id) ts, id from distinct_on_distributed where id in ('0') order by id, ts desc;
|
|
|
|
reset enable_sort; |