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Home -> Community -> Mailing Lists -> Oracle-L -> Re: Shared pool wait for library cache pin
George/Arun,
I see that bug
1640583
is present in 8.1.6.3
but I'm
having trouble
confirming that
it is present in 8.1.5.
How can I positively
confirm
that?
This bug text does not
mention
the timed_statistics
issue.
Is there some place
where
this connection is
documented.
I need something I can
show
the application owner
that has more details
than the
text of this bug has.
The
bug text itself is not
very
enlightening.
I don't see anything
else on
Metalink that has more
details.
Any further advice is
greatly
appreciated.
Cherie Machler
Oracle DBA
Gelco Information
Network
George
Schlossnagle To: Multiple recipients of list
ORACLE-L <ORACLE-L_at_fatcity.com>
<schlossnagle_at_py cc:
thian.com> Subject: Re: Shared pool wait for
library cache pin
Sent by:
root_at_fatcity.com
01/03/02 12:50
AM
Please respond
to ORACLE-L
Hi,
Queries with high version counts can cause library cache latch contention, as the query must hold that latch during soft parse and has to go through the entire list of query versions in the data dictionary. High version_count's are often caused by a high number of invalidations on the query. Invalidations of a query can be caused by a number of different things (one is the bug with timed_statistics, another is a bug present up to 8.1.6.3 in some instances when materialized views are used), other causes of invalidations are analyzing a dependent table or index, or truncating a dependent table.
If this is causing you a problem, the next step is to track down what the cause of your high version_counts is, and work to correct it or workaround it (depending on the frequency that the query is executed, a shared pool flush may remove all versions (or none)). If it's not causing you a service problem currently, I would still keep an eye on it, as the version_count for queries rises, the chances of getting severe contention on the library cache latch increases.
George
// George Schlossnagle // www.pythian.com -- schlossnagle_at_pythian.com -- 877-PYTHIAN // Smarter than adding another team member, Pythian has new services // for supplementing DBAs: get our help with monitoring, 24x7 on-call, // daily verifications, storage management, performance and more.
On Wednesday, January 2, 2002, at 04:35 PM, Cherie_Machler_at_gelco.com wrote:
>
> Yes, there are a handful with more than 400.
> I'm not sure what high is?
>
> Cherie
>
>
>
> "George
> Schlossnagle" To: Multiple recipients
> of list ORACLE-L <ORACLE-L_at_fatcity.com>
> <schlossnagle_at_py cc:
> thian.com> Subject: Re: Shared pool
> wait for library cache pin
> Sent by:
> root_at_fatcity.com
>
>
> 01/02/02 02:41
> PM
> Please respond
> to ORACLE-L
>
>
>
>
>
>
> Do any of your queries have a high version_count (visible through
> v$sqlarea)?
>
> George
>
> ----- Original Message -----
> To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
> Sent: Wednesday, January 02, 2002 3:20 PM
>
>
>>
>> We are seeing a lot of shared pool waits (for libary cache pin) on
>> our 8.1.5 web-based application. We are seeing this via
>> Precise/Indepth
>> SQL monitoring tool.
>>
>> I haven't been able to find much documentation on shared pool waits or
>> library cache pins.
>>
>> Can anyone tell me what might be causing this problem?
>>
>> Thanks,
>>
>> Cherie
>>
>> --
>> Please see the official ORACLE-L FAQ: http://www.orafaq.com
>> --
>> Author:
>> INET: Cherie_Machler_at_gelco.com
>>
>> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
>> San Diego, California -- Public Internet access / Mailing Lists
>> --------------------------------------------------------------------
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>> (or the name of mailing list you want to be removed from). You may
>> also send the HELP command for other information (like subscribing).
>>
>>
>
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: George Schlossnagle
> INET: schlossnagle_at_pythian.com
>
> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> San Diego, California -- Public Internet access / Mailing Lists
> --------------------------------------------------------------------
> To REMOVE yourself from this mailing list, send an E-Mail message
> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> the message BODY, include a line containing: UNSUB ORACLE-L
> (or the name of mailing list you want to be removed from). You may
> also send the HELP command for other information (like subscribing).
>
>
>
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author:
> INET: Cherie_Machler_at_gelco.com
>
> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> San Diego, California -- Public Internet access / Mailing Lists
> --------------------------------------------------------------------
> To REMOVE yourself from this mailing list, send an E-Mail message
> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> the message BODY, include a line containing: UNSUB ORACLE-L
> (or the name of mailing list you want to be removed from). You may
> also send the HELP command for other information (like subscribing).
>
>
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: INET: Cherie_Machler_at_gelco.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Thu Jan 03 2002 - 11:25:34 CST
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