RE: High db file sequential reads

  • From: "Khemmanivanh, Somckit" <somckit.khemmanivanh@xxxxxxxxxxxxxxxx>
  • To: <bbellows@xxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Mon, 13 Jun 2005 12:56:53 -0700

Yikes, you want to see a high number of waits?

Top 5 Timed Events
~~~~~~~~~~~~~~~~~~                                                     %
Event                                               Waits    Time (s)
Ela Time
-------------------------------------------- ------------ -----------
db file sequential read                        11,916,289      19,803
CPU time                                                       12,151
db file scattered read                          3,200,766         792
buffer busy waits                                 343,288         493
log file sync                                      61,583         403

You're numbers seem pretty typical...

-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Bellows, Bambi
Sent: Monday, June 13, 2005 12:19 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: High db file sequential reads

Hi Everybody!
I've been administering a system lately that's used almost exclusively
for Oracle Financials and one of the things that Oracle Financials does
every well is hide what it's doing.  Oh, sure, you can poke around in
v$sql but that doesn't really do much for you.  So I've been rather
dependent on statspack (lovely thing) and from there I can see what's
eating up time and analyze the structure and, as needed, apply indexes
to the tables.  There's not really much more you can do than that as you
have no access to the underlying queries, and, even if you did, you sure
couldn't change anything, database parameters aside, of course.  That
being said, these percentages seem out of whack to me... what do you
think? =20
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~                                                     %
Event                                               Waits    Time (s)
Ela Time
-------------------------------------------- ------------ -----------
db file sequential read                           438,536       2,792
CPU time                                                        1,284
db file scattered read                             32,239         165
log file parallel write                            12,667          14
SQL*Net break/reset to client                       1,384           9
^LWait Events for DB: PFIN  Instance: PFIN  Snaps: 3962 -3963
Has anyone successfully gotten db file sequential reads into any kind of
sane range for any period of time?
Thanks folks!



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