Re: "latch: cache buffers chains" wait in NON-RAC Benchmark Runs

  • From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
  • To: <bpmaclean.oracle@xxxxxxxxx>, <VIVEK_SHARMA@xxxxxxxxxxx>
  • Date: Fri, 15 Feb 2008 16:11:59 -0000


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@xxxxxxxxxxx> 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
         -------------------------------------------------------------


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