Re: Don't rely on 9i Skip Scan Indexing

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message
>
> Rule one when 'feature does not work' is
> to hint it in to find out what the cost of
> making it work is going to be.
>
> Try /*+ index_ss_asc */ with the query
> and you may find that a skip scan on
> your data set has a cost which is higher
> than the FTS..
>
>
> (You say the primary key has 6 values on
> a table of 66 rows - did you mean the leading
> column ? If so, the skip scan will probably
> have a cost of about 13)

Yes, this is the case. Sorry, I didn't make that clear.

> I have actually built data sets where the first
> two columns of an index are skipped automatically
> for a query that uses only the third.
>
>
> --
> Regards
>
> Jonathan Lewis

Johnathan,

Thank's for you feedback,

Greg Johnson
Oracle Certified Professional
OCP 8i DBA / OCP 9i DBA
Dialog Information Technology
Brisbane, Queensland, Australia Received on Mon Oct 21 2002 - 18:05:23 CDT