Re: When should one rebuild an index?
From: Bob Jones <email_at_me.not>
Date: Tue, 30 Dec 2008 22:21:31 -0600
Message-ID: <grC6l.7728$hc1.608@flpi150.ffdc.sbc.com>
> You may be ... I haven't wavered an angstrom.
>
> Perhaps you should reread this thread from the beginning.
> To be honest, and I should be, I intentionally let this thread mislead
> the conversation just to see if anyone had actually used ANALYZE INDEX
> to make these decisions.
> Given that I introduced a flagrant and obvious error the result to that
> question is clear.
> The functionality that might be used is ANALYZE INDEX <index_name>
> COMPUTE STATISTICS. That no one noticed I used VALIDATE STRUCTURE
> says what needs to be said.
> But, having run a full battery of tests using COMPUTE STATISTICS I will
> state, here and for the record, that it too provides a metrics that are
> not a reliable source of information as to whether an index would
> benefit from a rebuild.
Date: Tue, 30 Dec 2008 22:21:31 -0600
Message-ID: <grC6l.7728$hc1.608@flpi150.ffdc.sbc.com>
"DA Morgan" <damorgan_at_psoug.org> wrote in message
news:1230681064.435435_at_bubbleator.drizzle.com...
> Bob Jones wrote:
>> "DA Morgan" <damorgan_at_psoug.org> wrote in message >> news:1230565383.240290_at_bubbleator.drizzle.com... >>> Bob Jones wrote: >>> >>>> I am not surprised you reached this conclusion based on only the >>>> example above. >>> Rerun my demo and include any and all columns you wish. Then, using >>> those columns and the data they contain, make your case as to how it >>> constitutes sufficient information to determine an index should be >>> rebuilt. >> >> Sufficient information? Are we changing the topic again? >
> You may be ... I haven't wavered an angstrom.
>
Really? From irrelevance to sufficient information seems to be quite a shift to me.
>> What a simplistic approach to tuning. If I can make a conclusion that >> INDEX_STATS is useless just base on a Mickey Mouse example without any >> other data, life would be easy. Anyone has a crystal ball to lend? >
> Perhaps you should reread this thread from the beginning.
>
> To be honest, and I should be, I intentionally let this thread mislead
> the conversation just to see if anyone had actually used ANALYZE INDEX
> to make these decisions.
>
> Given that I introduced a flagrant and obvious error the result to that
> question is clear.
>
> The functionality that might be used is ANALYZE INDEX <index_name>
> COMPUTE STATISTICS. That no one noticed I used VALIDATE STRUCTURE
> says what needs to be said.
>
> But, having run a full battery of tests using COMPUTE STATISTICS I will
> state, here and for the record, that it too provides a metrics that are
> not a reliable source of information as to whether an index would
> benefit from a rebuild.
Neither of us need to reread the thread. I think it is very clear to everyone now. Received on Tue Dec 30 2008 - 22:21:31 CST