Re: speed questions

In article <3266DFD3.45D6_at_mail.albany.net>,

   Steve Rentz <capland_at_mail.albany.net> wrote:
>We have a 50 gig database in Oracle 7.1 (currently testing 7.3). Raw
>data consists of about 15 gig. We have the data denormalized to avoid
>joins. The amount of time it takes to get results from queries we feel
>is unacceptable (3 hours for an average query, 8 hours for anything
>complex). The database consists of 3 main tables (customers - 13 million
>records, orders - 27 million records, items - 80 million records). We
>are wondering if going to a star schema would improve performance? Any
>recommendations would be appreciated.

sounds like you are doing full scans, but to obtain advice you will need to show the net what an average query looks like.

P.S.: joins are not necessarily bad; a star schema will create potentially many joins, however. the trick is to let oracle scan a small table to reject all but the interesting rows, then perform joins to the larger entities. to do this successfully depends on what your query criteria may be.

Dave Mausner, Managing Consultant, Braun Technology Group, Chicago. Received on Fri Oct 18 1996 - 00:00:00 CEST