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Data Bases > Oracle Miscellaneous > Re: HowTo find ...
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Re: HowTo find out used (useful) and unused (usesless) indexes?

by "Shakespeare" <whatsin@[EMAIL PROTECTED] > Apr 20, 2008 at 10:05 AM

"DA Morgan" <damorgan@[EMAIL PROTECTED]
> schreef in bericht 
news:1208624947.696580@[EMAIL PROTECTED]
> Shakespeare wrote:
>
>> But an index may become useful over time, true?
>>
>> Shakespeare
>
> On that basis alone one could justify putting an index on every
> column of every table so I will respectfully disagree unless you
> write a very broad definition of "may."
>
> You need to understand your data and how it is being accessed.
> The extra overhead of an unused index is not value added.
>
> My recommendation would be to use the DBMS_STATS.SET.... procedures
> to see how queries will react to the expected future growth of both
> tables and indexes.
> -- 
> Daniel A. Morgan
> Oracle Ace Director & Instructor
> University of Wa****ngton
> damorgan@[EMAIL PROTECTED]
 (replace x with u to respond)
> Puget Sound Oracle Users Group
> www.psoug.org

I was aiming at data with for example a 'year' column. This column could
be 
indexed by design, but in the first year (all records same value) this
index 
is not useful and won't be used. But on the first entry in the second year

it is useful to find entries of that year and so on. A script to remove or

disable unused indexes would remove/disable this index in the first year.

Shakespeare
 




 14 Posts in Topic:
HowTo find out used (useful) and unused (usesless) indexes?
Andreas Mosmann <mosma  2008-04-17 11:38:22 
Re: HowTo find out used (useful) and unused (usesless) indexes?
"fitzjarrell@[EMAIL   2008-04-17 05:45:26 
Re: HowTo find out used (useful) and unused (usesless) indexes?
DA Morgan <damorgan@[E  2008-04-17 10:02:24 
Re: HowTo find out used (useful) and unused (usesless) indexes?
Andreas Mosmann <mosma  2008-04-18 11:29:40 
Re: HowTo find out used (useful) and unused (usesless) indexes?
joel garry <joel-garry  2008-04-18 14:45:00 
Re: HowTo find out used (useful) and unused (usesless) indexes?
yf110@[EMAIL PROTECTED]   2008-04-18 15:01:06 
Re: HowTo find out used (useful) and unused (usesless) indexes?
"Shakespeare" &  2008-04-19 11:37:36 
Re: HowTo find out used (useful) and unused (usesless) indexes?
DA Morgan <damorgan@[E  2008-04-19 10:09:08 
Re: HowTo find out used (useful) and unused (usesless) indexes?
"Shakespeare" &  2008-04-20 10:05:17 
Re: HowTo find out used (useful) and unused (usesless) indexes?
DA Morgan <damorgan@[E  2008-04-20 13:33:34 
Re: HowTo find out used (useful) and unused (usesless) indexes?
DA Morgan <damorgan@[E  2008-04-19 10:06:22 
Re: HowTo find out used (useful) and unused (usesless) indexes?
Andreas Mosmann <mosma  2008-04-21 18:37:17 
Re: HowTo find out used (useful) and unused (usesless) indexes?
Robert Klemme <shortcu  2008-04-21 01:24:52 
Re: HowTo find out used (useful) and unused (usesless) indexes?
joel garry <joel-garry  2008-04-21 11:46:53 

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tan12V112 Wed Dec 3 0:06:11 CST 2008.