INTERSECT QUESTION

I have a view called V_EMPLOYEES, which is a join of 3 tables. If I do this Select against the view:

SELECT EMP_ID FROM V_EMPLOYEES WHERE CITY = 'RESTON' the response is quick. If I do

SELECT EMP_ID FROM V_EMPLOYEES WHERE STATE = 'VA' the response is equally quick. If I do

SELECT EMP_ID FROM V_EMPLOYEES WHERE CITY = 'RESTON' AND STATE = 'VA' the response is painfully slow. But if I do an Intersect like the following

SELECT EMP_ID FROM V_EMPLOYEES WHERE CITY = 'RESTON' INTERSECT
SELECT EMP_ID FROM V_EMPLOYEES WHERE STATE = 'VA' the response is also quick.

Is there an explanation from such behavior?

Thanks,
Lito

Lito Dizon
adizon_at_us.net Received on Thu Dec 26 1996 - 00:00:00 CST