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MDEV-18467 Server crashes in fix_semijoin_strategies_for_picked_join_order

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If a splittable materialized derived table / view T is used in a inner nest
of an outer join with impossible ON condition then T is marked as a
constant table. Yet the execution plan to build T is still searched for
in spite of the fact that is not needed. So it should be set.
This commit is contained in:
Igor Babaev
2019-03-04 23:10:30 -08:00
parent a2fc36989e
commit 8f4de38f65
5 changed files with 81 additions and 6 deletions
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41
mysql-test/main/derived_split_innodb.result
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@@ -99,3 +99,44 @@ id select_type table type possible_keys key key_len ref rows Extra
2 LATERAL DERIVED t1 eq_ref PRIMARY PRIMARY 4 test.t2.id 1
set join_cache_level=default;
DROP TABLE t1,t2;
#
# Bug mdev-18467: join of grouping view and a base table as inner operand
# of left join with on condition containing impossible range
#
create table t1 (f1 int, f2 int, key(f2)) engine=InnoDB;
insert into t1 values (3,33), (7,77), (1,11);
create table t2 (f1 int, f2 int, primary key (f1)) engine=InnoDB;
insert into t2 values (3,33), (9,99), (1,11);
create view v1 as
select f1, max(f2) as f2 from t2 group by f1;
select t.f2
from t1
left join
(v1 join t1 as t on v1.f1=t.f1 and t.f2 = null)
on t1.f1=t.f1;
f2
NULL
NULL
NULL
explain select t.f2
from t1
left join
(v1 join t1 as t on v1.f1=t.f1 and t.f2 = null)
on t1.f1=t.f1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t const f2 NULL NULL NULL 1 Impossible ON condition
1 PRIMARY <derived2> const key1 NULL NULL NULL 1 Impossible ON condition
1 PRIMARY t1 ALL NULL NULL NULL NULL 3
2 DERIVED t2 ALL PRIMARY NULL NULL NULL 3 Using temporary; Using filesort
set statement optimizer_switch='split_materialized=off' for explain select t.f2
from t1
left join
(v1 join t1 as t on v1.f1=t.f1 and t.f2 = null)
on t1.f1=t.f1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t const f2 NULL NULL NULL 1 Impossible ON condition
1 PRIMARY <derived2> const key1 NULL NULL NULL 1 Impossible ON condition
1 PRIMARY t1 ALL NULL NULL NULL NULL 3
2 DERIVED t2 index NULL PRIMARY 4 NULL 3
drop view v1;
drop table t1,t2;