Re: Unnecessary table scans

> Has anyone come across this before and is it a known problem or a
> configuration issue ? We are running a datamart on 8.1.6 on AIX. All our
> fact tables have a composite primary key and bitmap indexes on the indidual
> columns of the primary keys. Statistics are adequate and up-to-date.
> A lot of our queries are however defaulting to a full table scan which is
> leading to long query times.
>
> An example of of timings would be
>
> A - Run query with no hints
> Time to run - 6 mins +
> Cost - 13736
>
> B - Run query forcing it to use composite index.
> Time to run - 1 min +
> Cost - 35558
>
> C - Run query forcing it to use bitmap indexes.
> Time to run - 10 secs
> Cost - 15478

What do you WHERE clauses look like? Give us an example from the above.

Daniel A. Morgan Received on Tue Apr 03 2001 - 16:46:41 CDT