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Re: reserved shared pool

From: aaaa wwwwww <>
Date: Wed, 27 Sep 2000 20:49:25 -0700
Message-Id: <>

 Dear Henry

Very good account of it indeed ! what about Performance part ? Pl.. throw some light on that aspect also



On Wed, 27 Sep 2000 18:15:36  
 Henry Poras wrote:

>I have something funny going on in my shared pool which I just can't figure
>out. I recently installed a new application which was spitting out
>occasional 4031 errors for a large function (this function has about 88
>inputs and 4 outputs. Yippee). When I started looking at v$sqlarea and
>v$db_object_cache (v7.3.4.5 on Solaris by the way), I saw that this function
>was being continually reloaded (different first_load_time with same
>hash_value). It showed a sharable_mem ranging from 50-70K, which was
>comparable to what I saw on v$db_object_cache. It also runs with multiple
>children. V$db_object_cache showed about a 3:1 ratio between executions and
>I decided to add a reserved piece to my shared pool. To get an idea of how
>large to make it, I did a sum of shared_mem for v$sqlarea and
>v$db_object_cache for everything, and for sharable_mem >= 5000. More than
>half of my memory usage seemed to be for sharable memory greater than 5K, so
>I made a 50:50 split in my shared pool. Now for the funny stuff. Most of my
>reserved pool (~90%) is not being used and nothing is being flushed out of
>it (v$shared_pool_reserved .request_failures = 0). My monster function is
>still being continually reloaded as per v$sqlarea with the same values (50K)
>for sharable_mem. V$db_object_cache, however, now shows this function with a
>sharable_mem of ~200 bytes (it actually fluctuates between 200 bytes and 2K
>as the function is loaded and freed). Finally, when I look at the load
>numbers for all objects in v$db_object_cache with sharable_mem >=5000, I
>expected to see low numbers, but that is not the case even though there is
>plenty of room in the reserved pool.
>I know I am missing something, but what? Has anyone else seen this? Thanks
>for the help.
>Please see the official ORACLE-L FAQ:
>Author: Henry Poras
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Received on Wed Sep 27 2000 - 22:49:25 CDT

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