mariadb/mysql-test/t/explain.test

#
# 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 <20><><EFBFBD> (<28><><EFBFBD>0 int, <20><><EFBFBD>1 int, key <20><><EFBFBD>0 (<28><><EFBFBD>0), key <20><><EFBFBD>01 (<28><><EFBFBD>0,<2C><><EFBFBD>1));
insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (1);
insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (2);
explain select <20><><EFBFBD>0 from <20><><EFBFBD> where <20><><EFBFBD>0=1;
drop table <20><><EFBFBD>;
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;


# 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 End of 5.1 tests.