mariadb/mysql-test/t/explain.test
Alexey Kopytov 97374a1184 Bug #48419: another explain crash..
WHERE predicates containing references to empty tables in a
subquery were handled incorrectly by the optimizer when
executing EXPLAIN. As a result, the optimizer could try to
evaluate such predicates rather than just stop with
"Impossible WHERE noticed after reading const tables" as 
it would do in a non-subquery case. This led to valgrind 
errors and crashes.

Fixed the code checking the above condition so that subqueries
are not excluded and hence are handled in the same way as top
level SELECTs.

mysql-test/r/explain.result:
  Added a test case for bug #48419.
mysql-test/r/ps.result:
  Updated test results to take the new (and more correct)
  "Extra" comments in execution plans.
mysql-test/t/explain.test:
  Added a test case for bug #48419.
sql/sql_select.cc:
  There is no point in excluding subqueries from checking
  for identically false WHERE conditions.
2010-04-30 15:10:48 +04:00

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#
# Test of different EXPLAIN's
--disable_warnings
drop table if exists t1;
--enable_warnings
create table t1 (id int not null, str char(10), unique(str));
explain select * from t1;
insert into t1 values (1, null),(2, null),(3, "foo"),(4, "bar");
select * from t1 where str is null;
select * from t1 where str="foo";
explain select * from t1 where str is null;
explain select * from t1 where str="foo";
explain select * from t1 ignore key (str) where str="foo";
explain select * from t1 use key (str,str) where str="foo";
#The following should give errors
--error 1176
explain select * from t1 use key (str,str,foo) where str="foo";
--error 1176
explain select * from t1 ignore key (str,str,foo) where str="foo";
drop table t1;
explain select 1;
create table t1 (a int not null);
explain select count(*) from t1;
insert into t1 values(1);
explain select count(*) from t1;
insert into t1 values(1);
explain select count(*) from t1;
drop table t1;
#
# Bug #3403 Wrong encoding in EXPLAIN SELECT output
#
set names koi8r;
create table ÔÁÂ (ËÏÌ0 int, ËÏÌ1 int, key ÉÎÄ0 (ËÏÌ0), key ÉÎÄ01 (ËÏÌ0,ËÏÌ1));
insert into ÔÁÂ (ËÏÌ0) values (1);
insert into ÔÁÂ (ËÏÌ0) values (2);
explain select ËÏÌ0 from ÔÁÂ where ËÏÌ0=1;
drop table ÔÁÂ;
set names latin1;
# End of 4.1 tests
#
# Bug#15463: EXPLAIN SELECT..INTO hangs the client (QB, command line)
#
select 3 into @v1;
explain select 3 into @v1;
#
# Bug#22331: Wrong WHERE in EXPLAIN EXTENDED when all expressions were
# optimized away.
#
create table t1(f1 int, f2 int);
insert into t1 values (1,1);
create view v1 as select * from t1 where f1=1;
explain extended select * from v1 where f2=1;
explain extended select * from t1 where 0;
explain extended select * from t1 where 1;
explain extended select * from t1 having 0;
explain extended select * from t1 having 1;
drop view v1;
drop table t1;
#
# Bug #32241: memory corruption due to large index map in 'Range checked for
# each record'
#
CREATE TABLE t1(c INT);
INSERT INTO t1 VALUES (),();
CREATE TABLE t2 (b INT,
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b),
KEY(b),KEY(b),KEY(b),KEY(b),KEY(b));
INSERT INTO t2 VALUES (),(),();
# We only need to make sure that there is no buffer overrun and the index map
# is displayed correctly
--replace_column 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X
EXPLAIN SELECT 1 FROM
(SELECT 1 FROM t2,t1 WHERE b < c GROUP BY 1 LIMIT 1) AS d2;
DROP TABLE t2;
DROP TABLE t1;
#
# Bug #34773: query with explain extended and derived table / other table
# crashes server
#
CREATE TABLE t1(a INT);
CREATE TABLE t2(a INT);
INSERT INTO t1 VALUES (1),(2);
INSERT INTO t2 VALUES (1),(2);
EXPLAIN EXTENDED SELECT 1
FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
EXPLAIN EXTENDED SELECT 1
FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
prepare s1 from
'EXPLAIN EXTENDED SELECT 1
FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1';
execute s1;
prepare s1 from
'EXPLAIN EXTENDED SELECT 1
FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1';
execute s1;
execute s1;
DROP TABLE t1,t2;
#
# Bug #43354: Use key hint can crash server in explain extended query
#
CREATE TABLE t1 (a INT PRIMARY KEY);
--error ER_KEY_DOES_NOT_EXITS
EXPLAIN EXTENDED SELECT COUNT(a) FROM t1 USE KEY(a);
DROP TABLE t1;
#
# Bug#45989 memory leak after explain encounters an error in the query
#
CREATE TABLE t1(a LONGTEXT);
INSERT INTO t1 VALUES (repeat('a',@@global.max_allowed_packet));
INSERT INTO t1 VALUES (repeat('b',@@global.max_allowed_packet));
--error ER_BAD_FIELD_ERROR
EXPLAIN SELECT DISTINCT 1 FROM t1,
(SELECT DISTINCTROW a AS away FROM t1 GROUP BY a WITH ROLLUP) as d1
WHERE t1.a = d1.a;
DROP TABLE t1;
--echo #
--echo # Bug#48295:
--echo # explain extended crash with subquery and ONLY_FULL_GROUP_BY sql_mode
--echo #
CREATE TABLE t1 (f1 INT);
SELECT @@session.sql_mode INTO @old_sql_mode;
SET SESSION sql_mode='ONLY_FULL_GROUP_BY';
# EXPLAIN EXTENDED (with subselect). used to crash. should give NOTICE.
--error ER_MIX_OF_GROUP_FUNC_AND_FIELDS
EXPLAIN EXTENDED SELECT 1 FROM t1
WHERE f1 > ALL( SELECT t.f1 FROM t1,t1 AS t );
SHOW WARNINGS;
SET SESSION sql_mode=@old_sql_mode;
DROP TABLE t1;
--echo End of 5.0 tests.
--echo #
--echo # Bug#37870: Usage of uninitialized value caused failed assertion.
--echo #
create table t1 (dt datetime not null, t time not null);
create table t2 (dt datetime not null);
insert into t1 values ('2001-01-01 1:1:1', '1:1:1'),
('2001-01-01 1:1:1', '1:1:1');
insert into t2 values ('2001-01-01 1:1:1'), ('2001-01-01 1:1:1');
flush tables;
EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
flush tables;
SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN (SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.dt IS NULL );
flush tables;
EXPLAIN SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
flush tables;
SELECT OUTR.dt FROM t1 AS OUTR WHERE OUTR.dt IN ( SELECT INNR.dt FROM t2 AS INNR WHERE OUTR.t < '2005-11-13 7:41:31' );
drop tables t1, t2;
--echo #
--echo # Bug#47669: Query showed by EXPLAIN EXTENDED gives different result from original query
--echo #
CREATE TABLE t1 (c int);
INSERT INTO t1 VALUES (NULL);
CREATE TABLE t2 (d int);
INSERT INTO t2 VALUES (NULL), (0);
EXPLAIN EXTENDED SELECT (SELECT 1 FROM t2 WHERE d = c) FROM t1;
DROP TABLE t1, t2;
--echo #
--echo # Bug #48419: another explain crash..
--echo #
CREATE TABLE t1 (a INT);
CREATE TABLE t2 (b BLOB, KEY b(b(100)));
INSERT INTO t2 VALUES ('1'), ('2'), ('3');
FLUSH TABLES;
EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT 1 FROM t1 t JOIN t2 WHERE b <= 1 AND t.a);
DROP TABLE t1, t2;
--echo End of 5.1 tests.