Re: Index Efficiency

From: Igor Neyman <igor.neyman_at_gmail.com>
Date: Sat, 20 Apr 2013 09:54:32 -0400
Message-ID: <CAJoeKmtE_vhEyJwt+T8gb+LDhx474LYB2v2rvVfYRwtWG8UAyg_at_mail.gmail.com>

Or, create partial/conditional indexes on the column with appropriate WHERE clause ("...where status = 1", or "where status = 2"...). Optimizer should know which one to use based on your query. Regards,
Igor Neyman

On Sat, Apr 20, 2013 at 12:19 AM, Mark W. Farnham <mwf_at_rsiz.com> wrote:

> I don't see the graph, but I do have a suggestion.
>
> Now I don't know whether "completed" or "declined" is a more popular value,
> but let's say most things end up "completed."
>
> If your applications can manage interpreting NULL as completed, then you
> can
> probably permanently and dramatically shrink the size of your index by
> using
> the value NULL instead of 1 for completed.
>
> This seems to match your brief description of your use case below. Your
> mileage may vary.
>
> mwf
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
> On Behalf Of oracledba
> Sent: Friday, April 19, 2013 10:20 PM
> To: Oracle-L Freelists
> Subject: Index Efficiency
>
> I have used Jonathan's index efficiency script to plot the graph.The graph
> is attached with this mail.
> This index is a single column index ( it's like a status column which has
> only 4 values say 1 - completed,2- declined,3-suspended,4-unknown).This
> table is populated every day and this column's values other than 1 and 2
> are
> updated with a new status based on daily's data.
> By looking at the graph,what do you infer? How effiecient the index is?
>
> Thanks
>
>
>
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Received on Sat Apr 20 2013 - 15:54:32 CEST