This fixes a performance issue: ORDER BY clauses in subqueries can make
the query unexpectedly slow. We should avoid this situation, since
ORM-generated queries have an ORDER BY clause which is not relevant in
the context of a subquery.
The following example was found:
SELECT "pos_payment"."id" AS "id"
FROM "pos_payment"
WHERE ("pos_payment"."pos_order_id" in
(SELECT "pos_order".id
FROM "pos_order"
WHERE ("pos_order"."company_id" in (1))
ORDER BY "pos_order"."id"))
AND "pos_payment".id IN (1285508)
Here are the query plans made by PostgreSQL on this query with and
without the ORDER BY clause. The query time went from 1240ms to
0.402ms, which is 3000 times faster!
EXPLAIN ANALYZE SELECT "pos_payment"."id" as "id" FROM "pos_payment" WHERE ("pos_payment"."pos_order_id" in (SELECT "pos_order".id FROM "pos_order" WHERE ("pos_order"."company_id" in (1)) ORDER BY "pos_order"."id" )) AND "pos_payment".id IN (1285508);
QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------------------
Merge Semi Join (cost=2.88..82726.85 rows=1 width=4) (actual time=1239.361..1239.364 rows=1 loops=1)
Merge Cond: (pos_payment.pos_order_id = pos_order.id)
-> Sort (cost=2.46..2.46 rows=1 width=8) (actual time=0.021..0.022 rows=1 loops=1)
Sort Key: pos_payment.pos_order_id
Sort Method: quicksort Memory: 25kB
-> Index Scan using pos_payment_pkey on pos_payment (cost=0.43..2.45 rows=1 width=8) (actual time=0.014..0.015 rows=1 loops=1)
Index Cond: (id = 1285508)
-> Index Scan using pos_order_pkey on pos_order (cost=0.43..66770.53 rows=1282120 width=4) (actual time=0.013..1148.194 rows=1182463 loops=1)
Filter: (company_id = 1)
Planning time: 0.272 ms
Execution time: 1239.396 ms
(11 rows)
EXPLAIN ANALYZE SELECT "pos_payment"."id" as "id" FROM "pos_payment" WHERE ("pos_payment"."pos_order_id" in (SELECT "pos_order".id FROM "pos_order" WHERE ("pos_order
"."company_id" in (1)) )) AND "pos_payment".id IN (1285508);
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------
Nested Loop (cost=0.85..4.89 rows=1 width=4) (actual time=0.047..0.049 rows=1 loops=1)
-> Index Scan using pos_payment_pkey on pos_payment (cost=0.43..2.45 rows=1 width=8) (actual time=0.027..0.028 rows=1 loops=1)
Index Cond: (id = 1285508)
-> Index Scan using pos_order_pkey on pos_order (cost=0.43..2.45 rows=1 width=4) (actual time=0.018..0.018 rows=1 loops=1)
Index Cond: (id = pos_payment.pos_order_id)
Filter: (company_id = 1)
Planning time: 0.322 ms
Execution time: 0.080 ms
(8 rows)
closesodoo/odoo#77357
X-original-commit: 947c3bd72ee84c3a298e0c9c365340ddf16b307d
Signed-off-by: Raphael Collet (rco) <rco@openerp.com>
Co-authored-by: Stanislas Sobieski (sts@odoo.com)
