Fix mark-and-restore-skipping test case to not be a self-join.

There isn't any good reason for this test to be a self-join rather
than a join between separate tables, except that it saved a couple
of SQL commands for setup.  A proposed patch to optimize away
self-joins breaks the test, so adjust it to avoid that happening.

Discussion: https://postgr.es/m/64486b0b-0404-e39e-322d-0801154901f3@postgrespro.ru
This commit is contained in:
Tom Lane 2019-02-21 18:55:29 -05:00
parent 0c7d537930
commit 24d08f3c0a
2 changed files with 22 additions and 13 deletions

View File

@ -5932,22 +5932,26 @@ left join j2 on j1.id1 = j2.id1 where j1.id2 = 1;
set enable_nestloop to 0;
set enable_hashjoin to 0;
set enable_sort to 0;
-- create an index that will be preferred over the PK to perform the join
-- create indexes that will be preferred over the PKs to perform the join
create index j1_id1_idx on j1 (id1) where id1 % 1000 = 1;
explain (costs off) select * from j1 j1
inner join j1 j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
create index j2_id1_idx on j2 (id1) where id1 % 1000 = 1;
-- need an additional row in j2, if we want j2_id1_idx to be preferred
insert into j2 values(1,2);
analyze j2;
explain (costs off) select * from j1
inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1;
QUERY PLAN
--------------------------------------------
QUERY PLAN
-----------------------------------------
Merge Join
Merge Cond: (j1.id1 = j2.id1)
Join Filter: (j1.id2 = j2.id2)
-> Index Scan using j1_id1_idx on j1
-> Index Scan using j1_id1_idx on j1 j2
-> Index Scan using j2_id1_idx on j2
(5 rows)
select * from j1 j1
inner join j1 j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
select * from j1
inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1;
id1 | id2 | id1 | id2
-----+-----+-----+-----

View File

@ -2014,15 +2014,20 @@ set enable_nestloop to 0;
set enable_hashjoin to 0;
set enable_sort to 0;
-- create an index that will be preferred over the PK to perform the join
-- create indexes that will be preferred over the PKs to perform the join
create index j1_id1_idx on j1 (id1) where id1 % 1000 = 1;
create index j2_id1_idx on j2 (id1) where id1 % 1000 = 1;
explain (costs off) select * from j1 j1
inner join j1 j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
-- need an additional row in j2, if we want j2_id1_idx to be preferred
insert into j2 values(1,2);
analyze j2;
explain (costs off) select * from j1
inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1;
select * from j1 j1
inner join j1 j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
select * from j1
inner join j2 on j1.id1 = j2.id1 and j1.id2 = j2.id2
where j1.id1 % 1000 = 1 and j2.id1 % 1000 = 1;
reset enable_nestloop;