1 delimiter $$
 2 drop procedure if exists proc_delete_old_data;
 3 create procedure proc_delete_old_data()
 4 begin
 5 lp : loop
 6     delete from mytable where createdtime <= date_sub(curdate(),interval 1 month) limit 5000;
 7     if row_count() < 5000 then
 8         leave lp;
 9     end if;
10     select sleep(1);
11 end loop;
12 end $$
13 
14 delimiter ;
15 set binlog_format = STATEMENT;
16 call proc_delete_old_data;