Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

1. Logically any SELECT is processed in following order:

   1. from
   2. where
   3. group by
   4. having
   5. olap functions
   6. qualify
   7. select
   8. sample
   9. order by

   Besides the proprietary QUALIFY/SAMPLE every DBMS will do it exactly …