mysql merge 引擎分表策略

DROP table IF EXISTS tb_member1;
create table tb_member1(
id bigint primary key auto_increment ,
name varchar(20),
sex tinyint not null default '0'
)ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

DROP table IF EXISTS tb_member2;
create table tb_member2 like tb_member1;
DROP table IF EXISTS tb_member3;
create table tb_member3 like tb_member1;

DROP table IF EXISTS tb_member;
create table tb_member(
id bigint primary key auto_increment ,
name varchar(20),
sex tinyint not null default '0'
)ENGINE=MERGE UNION=(tb_member1,tb_member2,tb_member3) INSERT_METHOD=LAST CHARSET=utf8 AUTO_INCREMENT=1 ;