Re: "latch: cache buffers chains" wait in NON-RAC Benchmark Runs
From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Fri, 15 Feb 2008 16:11:59 -0000
Message-ID: <013601c86fed$7f1d5460$0200a8c0@Primary>
>>
>> Folks
>>
>> In a Benchmark Run, 512 concurrent BATCH Processes using Dedicated
>> Sessions (NON-MTS) showing the following Waits:-
>>
>> Elapsed: 19.23 (mins)
>>
>> Top 5 Timed Events Avg
>> %Total
>> ~~~~~~~~~~~~~~~~~~
>> wait Call
>> Event Waits Time (s)
>> (ms) Time
>> ----------------------------------------- ------------ ----------- ------
>> ------
>> CPU
>> time 28,932
>> 27.2
>> latch: cache buffers chains 379,062 18,092
>> 48 17.0
>> db file scattered read
>> 134,021 17,649 132 16.6
>> db file sequential read 155,494 13,199
>> 85 12.4
>> SQL*Net break/reset to
>> client 4,314,656 10,430 2 9.8
>> -------------------------------------------------------------
Date: Fri, 15 Feb 2008 16:11:59 -0000
Message-ID: <013601c86fed$7f1d5460$0200a8c0@Primary>
Before commenting too much about the latch activity, I would want to know what sort of benchmark you are trying to create - given the balance of single and multi-block reads - and why you are expecting so many failed calls (break/reset) to the database.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
Author: Cost Based Oracle: Fundamentals
http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html
The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> On 2/14/08, VIVEK_SHARMA <VIVEK_SHARMA_at_infosys.com> wrote:
>>
>> Folks
>>
>> In a Benchmark Run, 512 concurrent BATCH Processes using Dedicated
>> Sessions (NON-MTS) showing the following Waits:-
>>
>> Elapsed: 19.23 (mins)
>>
>> Top 5 Timed Events Avg
>> %Total
>> ~~~~~~~~~~~~~~~~~~
>> wait Call
>> Event Waits Time (s)
>> (ms) Time
>> ----------------------------------------- ------------ ----------- ------
>> ------
>> CPU
>> time 28,932
>> 27.2
>> latch: cache buffers chains 379,062 18,092
>> 48 17.0
>> db file scattered read
>> 134,021 17,649 132 16.6
>> db file sequential read 155,494 13,199
>> 85 12.4
>> SQL*Net break/reset to
>> client 4,314,656 10,430 2 9.8
>> -------------------------------------------------------------
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Feb 15 2008 - 10:11:59 CST