optimizer not using function based indexes

From: Harvinder Singh <Harvinder.Singh_at_MetraTech.com>
Date: Thu, 09 May 2002 12:18:55 -0800
Message-ID: <F001.0045D821.20020509121855@fatcity.com>

Hi,

We are trying to use function based indexes in our application but it looks like optimizer is not using them.
So we created a sample table emp with 3 columns empno,ename,sal and populate this table with 100000 rows and created function based index on upper(ename). we try to run simple query like below and optimzer is not using index: select sal from emp
where upper(ename)=upper('abc98');

Even we use index hint optimizer is still not using index.....

1. table is analyzed as compute after creating index.
2. query rewrite is granted to user
3. query_rewrite_enabled=true.
4. optimzer mode is choose.
5. optimer should use index as there is no way full scan can be faster than index in this case as i tried to create simple index on ename and remove upper function from where clause of query..

What can be the possible reason that optimzer is not using index??????

Thanks
--Harvinder
--

Please see the official ORACLE-L FAQ: http://www.orafaq.com
--

Author: Harvinder Singh
  INET: Harvinder.Singh_at_MetraTech.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists


--------------------------------------------------------------------

To REMOVE yourself from this mailing list, send an E-Mail message

to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Thu May 09 2002 - 15:18:55 CDT