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Fixed LP bug #819716.

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Do not optimize derived table for the second time ever.
This commit is contained in:
Igor Babaev 2011-08-08 22:02:10 -07:00
parent 2ea5096cec
commit b7e9713ee3
5 changed files with 29 additions and 3 deletions
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15
mysql-test/r/derived_view.result
View file

@ -1200,4 +1200,19 @@ Warnings:
Note 1003 select `v2`.`b` AS `b` from `test`.`v2` where 0
DROP VIEW v1,v2;
DROP TABLE t1;
#
# LP bug #819716: crash with embedded tableless materialized derived
# with a variable
#
set optimizer_switch='derived_merge=off';
EXPLAIN
SELECT * FROM (SELECT * FROM (SELECT @b) AS t) AS s;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> system NULL NULL NULL NULL 1
2 DERIVED <derived3> system NULL NULL NULL NULL 1
3 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used
SELECT * FROM (SELECT * FROM (SELECT @b) AS t) AS s;
@b
NULL
set optimizer_switch=@exit_optimizer_switch;
set optimizer_switch=@exit_optimizer_switch;

2
mysql-test/r/subselect_sj.result
View file

@ -1284,7 +1284,7 @@ SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 2
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where; Using join buffer (flat, BNL join)
2 DEPENDENT SUBQUERY <derived3> ALL NULL NULL NULL NULL 2 Using where
2 DEPENDENT SUBQUERY <derived3> system NULL NULL NULL NULL 1
3 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used
SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
a a

2
mysql-test/r/subselect_sj_jcl6.result
View file

@ -1295,7 +1295,7 @@ SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 2
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where; Using join buffer (flat, BNL join)
2 DEPENDENT SUBQUERY <derived3> ALL NULL NULL NULL NULL 2 Using where
2 DEPENDENT SUBQUERY <derived3> system NULL NULL NULL NULL 1
3 DERIVED NULL NULL NULL NULL NULL NULL NULL No tables used
SELECT * FROM t1 INNER JOIN t2 ON t2.a != 0 AND t2.a IN (SELECT * FROM v1);
a a

11
mysql-test/t/derived_view.test
View file

@ -726,5 +726,16 @@ SELECT * FROM (SELECT b FROM v2 WHERE b = 0) t WHERE b;
DROP VIEW v1,v2;
DROP TABLE t1;
--echo #
--echo # LP bug #819716: crash with embedded tableless materialized derived
--echo # with a variable
--echo #
set optimizer_switch='derived_merge=off';
EXPLAIN
SELECT * FROM (SELECT * FROM (SELECT @b) AS t) AS s;
SELECT * FROM (SELECT * FROM (SELECT @b) AS t) AS s;
set optimizer_switch=@exit_optimizer_switch;
# The following command must be the last one the file
set optimizer_switch=@exit_optimizer_switch;

2
sql/sql_derived.cc
View file

@ -737,7 +737,7 @@ bool mysql_derived_optimize(THD *thd, LEX *lex, TABLE_LIST *derived)
bool res= FALSE;
if (unit->optimized && !unit->uncacheable && !unit->describe)
if (unit->optimized)
return FALSE;
lex->current_select= first_select;