There's something I don't understand. Why use
the wait interface to investigate "db file scattered read" or "db file
sequential read"?
The end result is finding an SQL statement that
does a lot of reads. There's no guarantee it's a poorly tuned SQL
statement, just that it does a lot of
Thats fine for expensive sql...but waits can be a
whole lot more than that...
(Trivial example)
session 1: delete from blah where x = 1;
session 2: delete from blah where x = 1;
session 3: delete from blah where x = 1;
etc
The wait stats will quickly show up the problem
here...
hth
connor
I personally believe that monitoring the SQLArea for any poor performing SQL
should also be done on a regular basis (*as well as monitoring the OWI
(:P)*).. The end result should be to build as complete a picture as possible
as to what is running through the system, where users are waiting, and
On Wed, Apr 24, 2002 at 05:33:25AM -0800, Connor McDonald wrote:
Thats fine for expensive sql...but waits can be a
whole lot more than that...
(Trivial example)
session 1: delete from blah where x = 1;
session 2: delete from blah where x = 1;
session 3: delete from blah where x = 1;
Thats fine for expensive sql...but waits can be a
whole lot more than that...
Agreed. I'm just asking about db file scattered read and db file
sequential read. What's the purpose of using the wait interface to
investigate these two events?
The accounts I've read of drilling down through the
Greg,
You wrote:
If your goal is to find SQL that does a lot of physical reads, why
not
forget about these two events? Just go to v$sql and sort by
physical reads.
Now you have a comprehensive picture of what's going on.
One of the problems with that is that you assume that 100 I/Os are always
that is freely
available!
** The opinions and statements above are entirely my own and not those of my
employer or clients **
-Original Message-
From: Greg Moore [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 24, 2002 2:08 PM
To: Multiple recipients of list ORACLE-L
Subject: Re: Why
Anjo,
You wrote:
The problem in Oracle is that wait events are
not broken down per SQL statement (only on the instance and session level).
There are products that out there that do this for you, but that would be
completely different post ;-)
I'll bite. Which products do
this?
Do
Moore [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 24, 2002 2:08 PM
To: Multiple recipients of list ORACLE-L
Subject: Re: Why wait?
Thats fine for expensive sql...but waits can be a
whole lot more than that...
Agreed. I'm just asking about db file scattered read and db file
and not those of
my
employer or clients **
-Original Message-
From: Greg Moore [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, April 24, 2002 2:08 PM
To: Multiple recipients of list ORACLE-L
Subject: Re: Why wait?
Thats fine for expensive sql...but waits can be a
whole lot more
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