RE: Books or links on Oracle Wait events (in depth)

What is nice explanation !!! You really hit the bulls eye.  

"Its just code"  

Regards,
Vishal Gupta
http://www.vishalgupta.com

From: oracle-l-bounce_at_freelists.org on behalf of Cary Millsap Sent: Tue 05/10/2010 12:43
To: shastry17_at_gmail.com
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_at_yahoo.com> 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_at_gmail.com>
	To: bdbafh_at_gmail.com
	Cc: shastry17_at_gmail.com; oracle-l <oracle-l_at_freelists.org>
	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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