drop table if exists t1; CREATE TABLE t1 ( STRING_DATA char(255) default NULL, KEY STRING_DATA (STRING_DATA) ) TYPE=MyISAM; INSERT INTO t1 VALUES ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'); INSERT INTO t1 VALUES ('DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD'); INSERT INTO t1 VALUES ('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF'); INSERT INTO t1 VALUES ('FGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG'); INSERT INTO t1 VALUES ('HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH'); INSERT INTO t1 VALUES ('WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW'); CHECK TABLE t1; Table Op Msg_type Msg_text test.t1 check status OK drop table t1; create table t1 (a tinyint not null auto_increment, b blob not null, primary key (a)); check table t1; Table Op Msg_type Msg_text test.t1 check status OK repair table t1; Table Op Msg_type Msg_text test.t1 repair status OK delete from t1 where (a & 1); check table t1; Table Op Msg_type Msg_text test.t1 check status OK repair table t1; Table Op Msg_type Msg_text test.t1 repair status OK check table t1; Table Op Msg_type Msg_text test.t1 check status OK drop table t1; create table t1 (a int not null auto_increment, b int not null, primary key (a), index(b)); insert into t1 (b) values (1),(2),(2),(2),(2); optimize table t1; Table Op Msg_type Msg_text test.t1 optimize status OK show index from t1; Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Comment t1 0 PRIMARY 1 a A 5 NULL NULL t1 1 b 1 b A 1 NULL NULL optimize table t1; Table Op Msg_type Msg_text test.t1 optimize status Table is already up to date show index from t1; Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Comment t1 0 PRIMARY 1 a A 5 NULL NULL t1 1 b 1 b A 1 NULL NULL drop table t1;