Re: Oracle Library Cache

From: Mark Bobak <Mark.Bobak_at_proquest.com>
Date: Wed, 23 Oct 2013 20:31:37 +0000
Message-ID: <CE8DA951.39906%Mark.Bobak_at_ProQuest.com>



Hi Matt,

My first thought would be, why were you compelled to look at that section of the AWR report? Do you have a performance problem? If so, what performance indicators pointed you in the direction of library cache hit ratios?

In general, looking at hit ratios in isolation is probably not a valid tuning strategy.

And no, I must admit, I dont know what SQL AREA STATS or SQL AREA BUILD means, in this context.

-Mark

On 10/23/13, 2:32 PM, "mvshelton_at_chartermi.net" <mvshelton_at_chartermi.net> wrote:

>SQL> select namespace,gets,gethits,round(gethitratio,2) gethitratio
> 2 from V$LIBRARYCACHE
> 3 where namespace like 'SQL%';
>
>NAMESPACE
>GETS
>----------------------------------------------------------------
>----------
> GETHITS GETHITRATIO
>---------- -----------
>SQL AREA
>13927433
> 13762659 .99
>
>SQL AREA STATS
>201188
> 27167 .14
>
>SQL AREA BUILD
>265640
> 109679 .41
>
>I noticed in my AWR report that a database had high pct misses for SQL
>AREA STATS of 87.56% and SQL AREA BUILD of 37% but I could not find any
>information that describes these library cache waits. I can query from
>v$library cache and get the hit ratio but I am not sure what this stat
>is. Any help would be appreciated.
>
>Thanks, Matt
>
>
>--
>http://www.freelists.org/webpage/oracle-l
>
>
>
>

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Received on Wed Oct 23 2013 - 22:31:37 CEST

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