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Enhancement. Buildfarm have detected curious unstability in the paral… #159

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Merged
merged 1 commit into from
Apr 26, 2023
Merged

Enhancement. Buildfarm have detected curious unstability in the paral… #159

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37 changes: 18 additions & 19 deletions expected/parallel_workers.out
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Original file line number Diff line number Diff line change
Expand Up @@ -68,53 +68,52 @@ WHERE q1.id = q2.id; -- Learning stage

-- XXX: Why grouping prediction isn't working here?
SELECT str FROM expln('
EXPLAIN (ANALYZE, COSTS OFF, TIMING OFF, SUMMARY OFF)
EXPLAIN (COSTS OFF, TIMING OFF, SUMMARY OFF)
SELECT count(*) FROM
(SELECT id FROM t WHERE id % 100 = 0 GROUP BY (id)) AS q1,
(SELECT max(id) AS id, payload FROM t
WHERE id % 101 = 0 GROUP BY (payload)) AS q2
WHERE q1.id = q2.id;') AS str
WHERE str NOT LIKE '%Workers%' AND str NOT LIKE '%Sort Method%'
AND str NOT LIKE '%Gather Merge%';
WHERE str NOT LIKE '%Workers%';
str
--------------------------------------------------------------------------------------------------
Aggregate (actual rows=1 loops=1)
Aggregate
AQO not used
-> Merge Join (actual rows=0 loops=1)
-> Merge Join
AQO not used
Merge Cond: (q2.id = t_1.id)
-> Sort (actual rows=1 loops=1)
-> Sort
Sort Key: q2.id
-> Subquery Scan on q2 (actual rows=1 loops=1)
-> Subquery Scan on q2
AQO not used
-> Finalize GroupAggregate (actual rows=1 loops=1)
-> Finalize GroupAggregate
AQO not used
Group Key: t.payload
-> Gather Merge
AQO not used
-> Partial GroupAggregate (actual rows=1 loops=3)
-> Partial GroupAggregate
AQO not used
Group Key: t.payload
-> Sort (actual rows=330 loops=3)
-> Sort
AQO not used
Sort Key: t.payload
-> Parallel Seq Scan on t (actual rows=330 loops=3)
AQO: rows=991, error=0%
-> Parallel Seq Scan on t
AQO: rows=991
Filter: ((id % '101'::numeric) = '0'::numeric)
Rows Removed by Filter: 33003
-> Group (actual rows=1000 loops=1)
-> Group
AQO not used
Group Key: t_1.id
-> Gather Merge
AQO not used
-> Group (actual rows=333 loops=3)
-> Group
AQO not used
Group Key: t_1.id
-> Sort (actual rows=333 loops=3)
-> Sort
AQO not used
Sort Key: t_1.id
-> Parallel Seq Scan on t t_1 (actual rows=333 loops=3)
AQO: rows=991, error=-1%
-> Parallel Seq Scan on t t_1
AQO: rows=991
Filter: ((id % '100'::numeric) = '0'::numeric)
Rows Removed by Filter: 33000
Using aqo: true
AQO mode: LEARN
JOINS: 1
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5 changes: 2 additions & 3 deletions sql/parallel_workers.sql
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Expand Up @@ -43,14 +43,13 @@ SELECT count(*) FROM
WHERE q1.id = q2.id; -- Learning stage
-- XXX: Why grouping prediction isn't working here?
SELECT str FROM expln('
EXPLAIN (ANALYZE, COSTS OFF, TIMING OFF, SUMMARY OFF)
EXPLAIN (COSTS OFF, TIMING OFF, SUMMARY OFF)
SELECT count(*) FROM
(SELECT id FROM t WHERE id % 100 = 0 GROUP BY (id)) AS q1,
(SELECT max(id) AS id, payload FROM t
WHERE id % 101 = 0 GROUP BY (payload)) AS q2
WHERE q1.id = q2.id;') AS str
WHERE str NOT LIKE '%Workers%' AND str NOT LIKE '%Sort Method%'
AND str NOT LIKE '%Gather Merge%';
WHERE str NOT LIKE '%Workers%';

RESET parallel_tuple_cost;
RESET parallel_setup_cost;
Expand Down