Re: [Maria-developers] f93af1f93e2: MDEV-12836 Avoid table rebuild when adding or removing of auto_increment settings

Hi, Eugene! On Feb 04, Eugene Kosov wrote:

...

  create table t1 (a int unique);   insert t1 values (NULL),(NULL),(NULL);   alter table t1 modify a int auto_increment;

create table t1 (a int not null, unique key a_key (a)) engine=innodb; insert into t1 values (19), (1), (100500); alter table t1 modify a int not null auto_increment,algorithm=instant; drop table t1;

You've missed the point. I wrote that in some cases ALTER TABLE has to generate auto-increment values. Try this example: create table t1 (a int not null, index (a)); insert t1 values (0),(0),(0); alter table t1 modify a int auto_increment; select * from t1; Regards, Sergei Chief Architect MariaDB and security@mariadb.org