text: use online_ddl;
  insert into t3 (uid, name, info) values (30004, 'name of 30004', '{"age": 30004}');
  insert into t2 (uid, name, info) values (50002, 'name of 50002', '{"age": 50002}');
  alter table t3 add column address varchar(255);
  alter table t2 add column address varchar(255);
  insert into t2 (uid, name, info, address) values (50003, 'name of 50003', '{"age": 50003}', 'address of 50003');
  insert into t3 (uid, name, info, address) values (30005, 'name of 30005', '{"age": 30005}', 'address of 30005');
  alter table t2 drop column age;
  alter table t3 drop column age;
  insert into t3 (uid, name, info, address) values (30006, 'name of 30006', '{"age": 30006}', 'address of 30006');
  insert into t2 (uid, name, info, address) values (50004, 'name of 50004', '{"age": 50004}', 'address of 50004');
  