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mariadb/mysql-test/r/explain.result
Alexey Kopytov f3a8307397 Bug #48537: difference of index selection between rpm binary 
and .tar.gz, windows vs linux..

On Intel x86 machines index selection by the MySQL query
optimizer could sometimes depend on the compiler version and
optimization flags used to build the server binary.

The problem was a result of a known issue with floating point
calculations on x86: since internal FPU precision (80 bit)
differs from precision used by programs (32-bit float or 64-bit
double), the result of calculating a complex expression may
depend on how FPU registers are allocated by the compiler and
whether intermediate values are spilled from FPU to memory. In
this particular case compiler versions and optimization flags
had an effect on cost calculation when choosing the best index
in best_access_path().

A possible solution to this problem which has already been
implemented in mysql-trunk is to limit FPU internal precision
to 64 bits. So the fix is a backport of the relevant code to
5.1 from mysql-trunk.

configure.in:
  Configure check for fpu_control.h
mysql-test/r/explain.result:
  Test case for bug #48537.
mysql-test/t/explain.test:
  Test case for bug #48537.
sql/mysqld.cc:
  Backport of the code to switch FPU on x86 to 64-bit precision.
2010-05-29 22:16:45 +04:00

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drop table if exists t1;
create table t1 (id int not null, str char(10), unique(str));
explain select * from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 system NULL NULL NULL NULL 0 const row not found
insert into t1 values (1, null),(2, null),(3, "foo"),(4, "bar");
select * from t1 where str is null;
id str
1 NULL
2 NULL
select * from t1 where str="foo";
id str
3 foo
explain select * from t1 where str is null;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref str str 11 const 1 Using where
explain select * from t1 where str="foo";
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const str str 11 const 1
explain select * from t1 ignore key (str) where str="foo";
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using where
explain select * from t1 use key (str,str) where str="foo";
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const str str 11 const 1
explain select * from t1 use key (str,str,foo) where str="foo";
ERROR 42000: Key 'foo' doesn't exist in table 't1'
explain select * from t1 ignore key (str,str,foo) where str="foo";
ERROR 42000: Key 'foo' doesn't exist in table 't1'
drop table t1;
explain select 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
create table t1 (a int not null);
explain select count(*) from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
insert into t1 values(1);
explain select count(*) from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
insert into t1 values(1);
explain select count(*) from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
drop table t1;
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;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE <09><><EFBFBD> ref <09><><EFBFBD>0,<2C><><EFBFBD>01 <09><><EFBFBD>0 5 const 1 Using where; Using index
drop table <20><><EFBFBD>;
set names latin1;
select 3 into @v1;
explain select 3 into @v1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
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;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00
Warnings:
Note 1003 select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
explain extended select * from t1 where 0;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
Warnings:
Note 1003 select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` where 0
explain extended select * from t1 where 1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00
Warnings:
Note 1003 select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
explain extended select * from t1 having 0;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible HAVING
Warnings:
Note 1003 select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` having 0
explain extended select * from t1 having 1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00
Warnings:
Note 1003 select '1' AS `f1`,'1' AS `f2` from `test`.`t1` having 1
drop view v1;
drop table t1;
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 (),(),();
EXPLAIN SELECT 1 FROM
(SELECT 1 FROM t2,t1 WHERE b < c GROUP BY 1 LIMIT 1) AS d2;
id select_type table type possible_keys key key_len ref rows Extra
X X X X X X X X X const row not found
X X X X X X X X X
X X X X X X X X X Range checked for each record (index map: 0xFFFFFFFFFF)
DROP TABLE t2;
DROP TABLE t1;
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;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
2 DERIVED t2 ALL NULL NULL NULL NULL 2 100.00 Using join buffer
Warnings:
Note 1003 select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
EXPLAIN EXTENDED SELECT 1
FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
2 DERIVED t2 ALL NULL NULL NULL NULL 2 100.00 Using join buffer
Warnings:
Note 1003 select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `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;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
2 DERIVED t2 ALL NULL NULL NULL NULL 2 100.00 Using join buffer
Warnings:
Note 1003 select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `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;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
2 DERIVED t2 ALL NULL NULL NULL NULL 2 100.00 Using join buffer
Warnings:
Note 1003 select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
execute s1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort
2 DERIVED t2 ALL NULL NULL NULL NULL 2 100.00 Using join buffer
Warnings:
Note 1003 select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
DROP TABLE t1,t2;
CREATE TABLE t1 (a INT PRIMARY KEY);
EXPLAIN EXTENDED SELECT COUNT(a) FROM t1 USE KEY(a);
ERROR 42000: Key 'a' doesn't exist in table 't1'
DROP TABLE t1;
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));
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;
ERROR 42S22: Unknown column 'd1.a' in 'where clause'
DROP TABLE t1;
#
# Bug#48295:
# explain extended crash with subquery and ONLY_FULL_GROUP_BY sql_mode
#
CREATE TABLE t1 (f1 INT);
SELECT @@session.sql_mode INTO @old_sql_mode;
SET SESSION sql_mode='ONLY_FULL_GROUP_BY';
EXPLAIN EXTENDED SELECT 1 FROM t1
WHERE f1 > ALL( SELECT t.f1 FROM t1,t1 AS t );
ERROR 42000: Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause
SHOW WARNINGS;
Level Code Message
Error 1140 Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause
Note 1003 select 1 AS `1` from `test`.`t1` where <not>(<exists>(...))
SET SESSION sql_mode=@old_sql_mode;
DROP TABLE t1;
End of 5.0 tests.
#
# Bug#37870: Usage of uninitialized value caused failed assertion.
#
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 );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY OUTR ALL NULL NULL NULL NULL 2 Using where
2 DEPENDENT SUBQUERY INNR ALL NULL NULL NULL NULL 2 Using where
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 );
dt
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' );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY OUTR ALL NULL NULL NULL NULL 2 Using where
2 DEPENDENT SUBQUERY INNR ALL NULL NULL NULL NULL 2 Using where
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' );
dt
2001-01-01 01:01:01
2001-01-01 01:01:01
drop tables t1, t2;
#
# Bug#47669: Query showed by EXPLAIN EXTENDED gives different result from original query
#
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;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 system NULL NULL NULL NULL 1 100.00
2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 100.00 Using where
Warnings:
Note 1276 Field or reference 'test.t1.c' of SELECT #2 was resolved in SELECT #1
Note 1003 select (select 1 from `test`.`t2` where (`test`.`t2`.`d` = NULL)) AS `(SELECT 1 FROM t2 WHERE d = c)` from `test`.`t1`
DROP TABLE t1, t2;
#
# Bug #48419: another explain crash..
#
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);
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 SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
DROP TABLE t1, t2;
#
# Bug #48573: difference of index selection between rpm binary and
# .tar.gz, windows vs linux..
#
CREATE TABLE t1(c1 INT, c2 INT, c4 INT, c5 INT, KEY(c2, c5), KEY(c2, c4, c5));
INSERT INTO t1 VALUES(4, 1, 1, 1);
INSERT INTO t1 VALUES(3, 1, 1, 1);
INSERT INTO t1 VALUES(2, 1, 1, 1);
INSERT INTO t1 VALUES(1, 1, 1, 1);
EXPLAIN SELECT c1 FROM t1 WHERE c2 = 1 AND c4 = 1 AND c5 = 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref c2,c2_2 c2 10 const,const 3 Using where
DROP TABLE t1;
End of 5.1 tests.
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