RE: Books or links on Oracle Wait events (in depth)
- From: "Vishal Gupta" <vishal@xxxxxxxxxxxxxxx>
- To: <cary.millsap@xxxxxxxxxxxx>, <shastry17@xxxxxxxxx>
- Date: Tue, 5 Oct 2010 17:50:09 +0100
Carry,
What is nice explanation !!! You really hit the bulls eye.
"Its just code"
Regards,
Vishal Gupta
http://www.vishalgupta.com
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx on behalf of Cary Millsap
Sent: Tue 05/10/2010 12:43
To: shastry17@xxxxxxxxx
Cc: oracle-l
Subject: Re: Books or links on Oracle Wait events (in depth)
See also section 18 of
http://method-r.com/downloads/doc_details/10-for-developers-making-friends-with-the-oracle-database-cary-millsap
The best place to learn what the Oracle timed events mean is the strace (truss,
etc) manual page. Activate Oracle extended SQL trace an Oracle kernel (shadow)
process, and strace it at the same time. In your strace output, you can see the
Oracle kernel process's write() calls to its trace file. The syscall(s) that
occur preceding each write is what you look up in the strace man page. This is
how you learn things like (on my 10.2 instance on RHEL r3):
* A db file scattered read is an __llseek() call and a readv() call.
* A db file sequential read is a pread() call.
* An enqueue is a semtimedop() call.
The *nix documentation for these syscalls is very clear, yet if you have any
remaining doubts about what's going on, you can even view the Linux source code
for what these calls are doing and how they do it.
Once you learn how the Oracle kernel interacts with its underlying operating
system, everything starts to fall right into place. It's just code.
Cary Millsap
Method R Corporation
http://method-r.com
http://carymillsap.blogspot.com
On Tue, Oct 5, 2010 at 5:34 AM, Chris Dunscombe <cdunscombe@xxxxxxxxx> wrote:
I'll second the book recommendation. It's a great book and the best
I've seen on the subject.
Chris
________________________________
From: kyle Hailey <kylelf@xxxxxxxxx>
To: bdbafh@xxxxxxxxx
Cc: shastry17@xxxxxxxxx; oracle-l <oracle-l@xxxxxxxxxxxxx>
Sent: Tue, 5 October, 2010 5:03:13
Subject: Re: Books or links on Oracle Wait events (in depth)
I'll second what Paul said
and if you still want to learn about the waits, I've put up a bunch of
non-RAC wait documentation at
https://sites.google.com/site/embtdbo/wait-event-documentation
The only decent book I'm aware of is The Oracle Wait Interface, see on
Amazon http://tinyurl.com/2ck8nc4
The Oracle documentation itself has gotten better over the years
Best Wishes
Kyle Hailey
http://db-optimizer.blogspot.com/
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