Q: Conditions order in WHERE clause

Hi,

Does somebody know in what order are WHERE conditions evaluated? Is it determined or is the final decision made by an optimizer?

E.g.:

select ...
   from ...
 where A1.A = 5                            -- c1
             and A1.B = A2.B             -- c2
             and A1.C = A3.C (+)       -- c3
             and A2.D is NULL           -- c4

Is this evaluated as it is written? :
c1 first then c2, c3 and finally c4?

How to ensure join conditions be evaluated first?

TIA --
Thank you for keeping >anti-spam< habit: not including my address in your reply. Received on Wed Jul 28 1999 - 08:25:22 CDT