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author | unknown <timour@askmonty.org> | 2011-12-19 23:05:44 +0200 |
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committer | unknown <timour@askmonty.org> | 2011-12-19 23:05:44 +0200 |
commit | 072073c09e0308ac58f1dbd2ee8f0fbc53e11467 (patch) | |
tree | 911303f982b3ef2f46cb003acbedcb269fedfb3b /mysql-test/suite/innodb/r/innodb_mysql.result | |
parent | 15ea7238e42ea62da32c926c0a1667802f7646d9 (diff) | |
download | mariadb-git-072073c09e0308ac58f1dbd2ee8f0fbc53e11467.tar.gz |
Backport of WL#5953 from MySQL 5.6
The patch differs from the original MySQL patch as follows:
- All test case differences have been reviewed one by one, and
care has been taken to restore the original plan so that each
test case executes the code path it was designed for.
- A bug was found and fixed in MariaDB 5.3 in
Item_allany_subselect::cleanup().
- ORDER BY is not removed because we are unsure of all effects,
and it would prevent enabling ORDER BY ... LIMIT subqueries.
- ref_pointer_array.m_size is not adjusted because we don't do
array bounds checking, and because it looks risky.
Original comment by Jorgen Loland:
-------------------------------------------------------------
WL#5953 - Optimize away useless subquery clauses
For IN/ALL/ANY/SOME/EXISTS subqueries, the following clauses are
meaningless:
* ORDER BY (since we don't support LIMIT in these subqueries)
* DISTINCT
* GROUP BY if there is no HAVING clause and no aggregate
functions
This WL detects and optimizes away these useless parts of the
query during JOIN::prepare()
Diffstat (limited to 'mysql-test/suite/innodb/r/innodb_mysql.result')
-rw-r--r-- | mysql-test/suite/innodb/r/innodb_mysql.result | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mysql-test/suite/innodb/r/innodb_mysql.result b/mysql-test/suite/innodb/r/innodb_mysql.result index d4bc8bc662b..4dcce4d0373 100644 --- a/mysql-test/suite/innodb/r/innodb_mysql.result +++ b/mysql-test/suite/innodb/r/innodb_mysql.result @@ -1425,9 +1425,9 @@ DROP TABLE t1; create table t1 (a bit(1) not null,b int) engine=myisam; create table t2 (c int) engine=innodb; set @save_optimizer_switch=@@optimizer_switch; -set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=off'; +set @@optimizer_switch='in_to_exists=on,materialization=off'; explain -select b from t1 where a not in (select b from t1,t2 group by a) group by a; +select b from t1 where a not in (select max(b) from t1,t2 group by a) group by a; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables 2 DEPENDENT SUBQUERY t1 system NULL NULL NULL NULL 0 const row not found |