select cola,colb from (select tab.*,dbms_random.random num from tab order by num) where rownum< N+1; select * from (select * from tablename order by sys_guid()) where rownum < N; select * from (select * from tablename order by dbms_random.value) where rownum< N;
by num) where rownum< N+1;
select * from (select * from tablename order by sys_guid()) where rownum < N;
select * from (select * from tablename order by dbms_random.value) where rownum< N;