SELECT @@GLOBAL.innodb_use_sys_malloc;
@@GLOBAL.innodb_use_sys_malloc
1
1 Expected
SET @@GLOBAL.innodb_use_sys_malloc=0;
ERROR HY000: Variable 'innodb_use_sys_malloc' is a read only variable
Expected error 'Read only variable'
SELECT @@GLOBAL.innodb_use_sys_malloc;
@@GLOBAL.innodb_use_sys_malloc
1
1 Expected
create table t1(a int not null,key(a,a)) engine=innodb DEFAULT CHARSET=latin1;
ERROR 42S21: Duplicate column name 'a'
create table t1(a int,b text,key(b(768))) engine=innodb DEFAULT CHARSET=latin1;
ERROR HY000: Index column size too large. The maximum column size is 767 bytes.
create table t1(a int not null,b text) engine=innodb DEFAULT CHARSET=latin1;
insert into t1 values (1,''),(2,''),(3,''),(4,''),(5,''),(6,''),(7,'');
create index t1aa on t1(a,a);
ERROR 42S21: Duplicate column name 'a'
create index t1b on t1(b(768));
ERROR HY000: Index column size too large. The maximum column size is 767 bytes.
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) NOT NULL,
  `b` text
) ENGINE=InnoDB DEFAULT CHARSET=latin1
select * from t1;
a	b
1	
2	
3	
4	
5	
6	
7	
drop table t1;
CREATE TABLE t2(a int primary key, b text) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO t2 VALUES (1,''),(2,''),(3,''),(4,''),(5,''),(6,''),(7,'');
CREATE INDEX t2aa on t2(a,a);
ERROR 42S21: Duplicate column name 'a'
CREATE INDEX t2b on t2(b(768));
ERROR HY000: Index column size too large. The maximum column size is 767 bytes.
SELECT * FROM t2;
a	b
1	
2	
3	
4	
5	
6	
7	
DROP TABLE t2;