2001-09-27 23:05:54 -06:00
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drop table if exists t1;
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create table t1 (id int not null, str char(10), unique(str));
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2003-01-20 18:17:14 +02:00
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explain select * from t1;
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2003-01-21 21:07:59 +02:00
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 system NULL NULL NULL NULL 0 const row not found
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2001-09-27 23:05:54 -06:00
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insert into t1 values (1, null),(2, null),(3, "foo"),(4, "bar");
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select * from t1 where str is null;
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2000-12-28 03:56:38 +02:00
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id str
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1 NULL
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2 NULL
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2001-09-27 23:05:54 -06:00
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select * from t1 where str="foo";
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2000-12-28 03:56:38 +02:00
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id str
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3 foo
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2001-09-27 23:05:54 -06:00
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explain select * from t1 where str is null;
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2002-09-26 23:08:22 +03:00
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id select_type table type possible_keys key key_len ref rows Extra
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2002-11-21 15:56:48 +02:00
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1 SIMPLE t1 ref str str 11 const 1 Using where
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2001-09-27 23:05:54 -06:00
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explain select * from t1 where str="foo";
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2002-09-26 23:08:22 +03:00
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id select_type table type possible_keys key key_len ref rows Extra
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2002-10-03 18:47:04 +03:00
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1 SIMPLE t1 const str str 11 const 1
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2001-09-27 23:05:54 -06:00
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explain select * from t1 ignore key (str) where str="foo";
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2002-09-26 23:08:22 +03:00
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id select_type table type possible_keys key key_len ref rows Extra
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2002-11-21 15:56:48 +02:00
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1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using where
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2001-09-27 23:05:54 -06:00
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explain select * from t1 use key (str,str) where str="foo";
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2002-09-26 23:08:22 +03:00
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id select_type table type possible_keys key key_len ref rows Extra
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2002-10-03 18:47:04 +03:00
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1 SIMPLE t1 const str str 11 const 1
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2001-09-27 23:05:54 -06:00
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explain select * from t1 use key (str,str,foo) where str="foo";
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2006-06-06 20:21:36 +03:00
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ERROR 42000: Key 'foo' doesn't exist in table 't1'
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2001-09-27 23:05:54 -06:00
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explain select * from t1 ignore key (str,str,foo) where str="foo";
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2006-06-06 20:21:36 +03:00
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ERROR 42000: Key 'foo' doesn't exist in table 't1'
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2001-09-27 23:05:54 -06:00
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drop table t1;
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explain select 1;
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2002-09-26 23:08:22 +03:00
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id select_type table type possible_keys key key_len ref rows Extra
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2002-12-14 17:43:01 +02:00
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
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2003-02-07 17:57:07 +02:00
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create table t1 (a int not null);
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explain select count(*) from t1;
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2003-02-08 02:09:21 +02:00
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
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2003-02-07 17:57:07 +02:00
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insert into t1 values(1);
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explain select count(*) from t1;
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2003-02-08 02:09:21 +02:00
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
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2003-02-07 17:57:07 +02:00
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insert into t1 values(1);
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explain select count(*) from t1;
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2003-02-08 02:09:21 +02:00
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
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2003-02-07 17:57:07 +02:00
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drop table t1;
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2004-05-14 13:08:22 +05:00
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set names koi8r;
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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));
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insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (1);
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insert into <20><><EFBFBD> (<28><><EFBFBD>0) values (2);
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explain select <20><><EFBFBD>0 from <20><><EFBFBD> where <20><><EFBFBD>0=1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE <09><><EFBFBD> ref <09><><EFBFBD>0,<2C><><EFBFBD>01 <09><><EFBFBD>0 5 const 1 Using where; Using index
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drop table <20><><EFBFBD>;
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set names latin1;
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2006-05-03 18:02:43 +04:00
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select 3 into @v1;
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explain select 3 into @v1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
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2007-03-07 21:44:58 +03:00
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create table t1(f1 int, f2 int);
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insert into t1 values (1,1);
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create view v1 as select * from t1 where f1=1;
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explain extended select * from v1 where f2=1;
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2007-03-08 20:57:12 +04:00
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00
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2007-03-07 21:44:58 +03:00
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Warnings:
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2007-03-10 00:29:02 +03:00
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Note 1003 select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
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2007-03-07 21:44:58 +03:00
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explain extended select * from t1 where 0;
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2007-03-08 20:57:12 +04:00
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
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2007-03-07 21:44:58 +03:00
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Warnings:
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Note 1003 select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` where 0
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explain extended select * from t1 where 1;
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2007-03-08 20:57:12 +04:00
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00
|
2007-03-07 21:44:58 +03:00
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|
Warnings:
|
2007-03-10 00:29:02 +03:00
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Note 1003 select '1' AS `f1`,'1' AS `f2` from `test`.`t1` where 1
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2007-03-07 21:44:58 +03:00
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explain extended select * from t1 having 0;
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2007-03-08 20:57:12 +04:00
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible HAVING
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2007-03-07 21:44:58 +03:00
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Warnings:
|
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|
Note 1003 select `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` having 0
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explain extended select * from t1 having 1;
|
2007-03-08 20:57:12 +04:00
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00
|
2007-03-07 21:44:58 +03:00
|
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|
|
Warnings:
|
2007-03-10 00:29:02 +03:00
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Note 1003 select '1' AS `f1`,'1' AS `f2` from `test`.`t1` having 1
|
2007-03-08 00:27:42 +03:00
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drop view v1;
|
2007-03-07 21:44:58 +03:00
|
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|
drop table t1;
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