create table big_table as
select rownum id, a.*
from all_objects a
where 1=0;
insert into big_table
select rownum id, a.*
from all_objects a
connect by level <= 1000000;
.
.
select t1.object_name, t2.object_name
from big_table t1, big_table t2
where t1.id = t2.id
and t1.owner = 'WMSYS'