RE: indexes

Hi, I found this in the oracle concept manual

Composite indexes can speed retrieval of data for SELECT statements in which the
WHERE clause references all or the leading portion of the columns in the compos-ite
index. Therefore, the order of the columns used in the definition is important;
generally, the most commonly accessed or most selective columns go first.

I hope this will help u

 Regards
 Vinayaka Holla.   

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The trouble with doing anything right the first time is that nobody appreciates how difficult it was. - Anon

> -----Original Message-----
> From: Webber Valerie H [SMTP:Valerie.H.Webber_at_irs.gov]
> Sent: Tuesday, May 09, 2000 8:40 PM
> To: Multiple recipients of list ORACLE-L
> Subject: indexes
>
> I know this issue has been discussed before but I can't find the answer in
> my list archives.
>
> If you have a composite index on a table consisting of columns A,B,C in
> that order, will the index be used if I have a query/where clause on
> columns A and C?
>
> I know that it will if I query on A alone or A,B or A,B,C but I can't find
> documentation about A and C (no B)
>
> Thanks in advance!
> Val
>
> Valerie H. Webber
> Management Systems Designers, Inc
> Valerie.H.Webber_at_m1.irs.gov
Received on Wed May 10 2000 - 00:29:47 CDT