RE: statspack wait events
- From: "Cary Millsap" <cary.millsap@xxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Wed, 4 Feb 2004 13:51:19 -0600
Raghu,
This kind of situation is what I meant by my "worse than useless" posts
last week... What you're showing *may* be an indication that you have
some SQL that would benefit from a reduction in OS read calls. However,
it is entirely possible that you also might *not* benefit from such a
reduction. If that's your situation, then you have an extra problem now:
getting the idea that you "have an I/O bottleneck" out of your head. If
your system does not have an I/O problem (and you can't tell by looking
at what you've shown here), then getting the wrong idea out of your head
is going to be an extra project step. In my experience, it's a project
step that sometimes takes MONTHS to execute. (Seeing this kind of thing
so frequently is what inspires great passion within me about this
subject.)
Your next step is to find some user action that's running for longer
than the business needs it to run. Find out why that program is taking
so long. Fix the program by reducing its demand for the thing it spends
the most time using. Once you've done that, if the program still isn't
fast enough for the business, then reduce the demand that its
competitors are generating for the resource your program is spending
most of its time consuming. Check Chapter 1 of "Optimizing Oracle
Performance" online (free) at
http://www.oreilly.com/catalog/optoraclep/index.html.
Somebody will surely recommend that you consult listing of "top SQL" in
the Statspack report you're looking at. By doing this, you'll probably
find something to work on. However, Statspack has no idea how to sort
your system's SQL statement by business priority, so it's possible that
the guidance you'll receive from this Statspack report won't help you at
all.
Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
* Nullius in verba *
Upcoming events:
- Performance Diagnosis 101: 2/24 San Diego, 3/23 Park City, 4/6 Seattle
- SQL Optimization 101: 2/16 Dallas
- Hotsos Symposium 2004: March 7-10 Dallas
- Visit www.hotsos.com for schedule details...
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Raghu Kota (WBTQ)
Sent: Wednesday, February 04, 2004 1:26 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: statspack wait events
Hi Friends,
I have concern regarding wait events got from statspack, So dilemma is =
what action I need to take now?? Any ideas will appreciated. My =
environment is oracle8174 on AIX51.
Top 5 Wait Events
~~~~~~~~~~~~~~~~~ Wait %
=
Total
Event Waits Time (cs) =
Wt Time
-------------------------------------------- ------------ ------------ =
-------
db file sequential read 145,479 20,055
=
49.21
log file sync 4,549 6,466
=
15.87
db file parallel write 252 5,134
=
12.60
log file parallel write 4,560 4,784
=
11.74
control file parallel write 326 2,165
=
5.31
Thanks again
Raghu.
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx
put 'unsubscribe' in the subject line.
--
Archives are at //www.freelists.org/archives/oracle-l/
FAQ is at //www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------
----------------------------------------------------------------
Please see the official ORACLE-L FAQ: http://www.orafaq.com
----------------------------------------------------------------
To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx
put 'unsubscribe' in the subject line.
--
Archives are at //www.freelists.org/archives/oracle-l/
FAQ is at //www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------
Other related posts:
