mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2026-05-15 03:17:20 +02:00
Code Issues Projects Releases Packages Wiki Activity

Bug#48483 crash in get_best_combination()

Browse source 
The crash happens because greedy_serach
can not determine best plan due to
wrong inner table dependences. These
dependences affects join table sorting
which performs before greedy_search starting.
In our case table which has real 'no dependences'
should be put on top of the list but it does not
happen as inner tables have no dependences as well.
The fix is to exclude RAND_TABLE_BIT mask from
condition which checks if table dependences
should be updated.


mysql-test/r/join.result:
  test result
mysql-test/t/join.test:
  test case
sql/sql_select.cc:
  RAND_TABLE_BIT mask should not be counted as it
  prevents update of inner table dependences.
  For example it might happen if RAND() function
  is used in JOIN ON clause.
This commit is contained in:
Sergey Glukhov 2010-03-24 14:37:28 +04:00
commit bccf219bfc
3 changed files with 41 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

12
mysql-test/t/join.test
View file

@ -713,4 +713,16 @@ FROM
DROP TABLE t1,t2,t3,t4,t5,t6;
--echo #
--echo # Bug#48483: crash in get_best_combination()
--echo #
CREATE TABLE t1(f1 INT);
INSERT INTO t1 VALUES (1),(2);
CREATE VIEW v1 AS SELECT 1 FROM t1 LEFT JOIN t1 AS t2 on 1=1;
EXPLAIN EXTENDED
SELECT 1 FROM v1 right join v1 AS v2 ON RAND();
DROP VIEW v1;
DROP TABLE t1;
--echo End of 5.0 tests.