drop table t1;
create table t1 (a integer, b text);
insert into t1 values(1, 'DATA_1');
insert into t1 values(2, 'DATA_2');
insert into t1 values(3, 'DATA_3');
insert into t1 values(4, 'DATA_4');
insert into t1 values(5, 'DATA_5');
insert into t1 values(6, 'DATA_6');

drop table t2;
create table t2 (c integer, d text);
insert into t2 values(4, 'DATA_4');
insert into t2 values(5, 'DATA_5');
insert into t2 values(6, 'DATA_6');
insert into t2 values(7, 'DATA_7');
insert into t2 values(8, 'DATA_8');
insert into t2 values(9, 'DATA_9');