Re: How can I make it faster? Help needed.

Have you tried a solution using "where not exists (...subquery specification...)"

I've often got better performance out of this than out of "NOT IN".

I'm right on my way out to wrk now, so I don't have time to figure out what the subquery would look like. Perhaps you can do it yourself, or perhaps I'll provide it in a later post.

Good Luck,

   Dave Cressey mailto:david_at_dcressey.com

Dr. Wei Ho wrote in message <371AF6C9.41C67EA6_at_etl.ericsson.se>...
>Hi,
>
>Can anybody out there help me to make the following query faster.
>
>Both tables, MESSAGE and CUSTOMER, in the query have about 13,000
>records. In both tables, the fields CUST_NO are indexed.
>
>SELECT m.cust_no
> FROM message m
> WHERE m.cust_no
>NOT IN (SELECT c.cust_no FROM customer c);
>
>Thanks
>
>Wei
Received on Mon Apr 19 1999 - 13:01:57 CEST