Re: Function based nvl index

From: Tim Gorman <tim_at_evdbt.com>
Date: Tue, 23 Apr 2013 07:01:15 -0600
Message-ID: <5176861B.5040604_at_evdbt.com>

The OP might also want to look into Mark Farnham's presentations on disappearing indexes (i.e.
"http://www.technicalconferencesolutions.com/pls/caat/caat_abstract_reports.display_presenter_abstract?conference_id=99&presenter_id=364&abstract_id=294976"), just in case the application logic is a match for this scenario.

On 4/23/2013 6:31 AM, Niall Litchfield wrote:
> How many nulls do you have as a percentage of the table, and does Oracle
> make a good estimate for this figure? Do you have any histograms in the
> column, as I expect you have 2 popular values and very little else?
> Formatted output from dbms_xlpan.display_cursor with plan execution stats
> would be extremely useful
> On Apr 23, 2013 1:17 PM, <rajugaru.vij_at_gmail.com> wrote:
>
>> Hi,
>> I have a situation where my function based index is not getting used. Its
>> an NVL based functional index
>>
>> NVL(gender,0) =0
>>
>> Is my where clause. And I have a index on NVL(gender,0)
>>
>> It was getting used previously, but not now.

--
http://www.freelists.org/webpage/oracle-l

Received on Tue Apr 23 2013 - 15:01:15 CEST