Re: Training for Oracle Performance tuning
- From: "Jared Still" <jkstill@xxxxxxxxx>
- To: fmhabash@xxxxxxxxx
- Date: Fri, 28 Sep 2007 09:22:16 -0700
Some comments inline:
On 9/26/07, fmhabash <fmhabash@xxxxxxxxx> wrote:
>
> Having said that, I have 4 reservations on HS M-R approach ...
>
> - This approach refuses to give any attention to instance level tuning.
> On some occasions, they won't even read a statspack report. Its entire
> focus is on identifying most important tasks for the business and
> collecting diagnostic data on it. This sounds great in concept, but in
> real life, it does not work this way. First, most often than not (at
> least in my experience), users and their managers, have no time (and
> sometimes knowledge) even to agree on a list. System is slow and we need
> to know why NOW. You will find out when such issue strikes, you won't
> have the time or initiative to ask people on the call to go back and a
> gather a list so you can have time to instrument your database to
> collect stats. Specially, if your application users MTS, connection
> pools, or in large RAC environment.
When we have had performance problems, the users/mgrs have always
been more than willing to help me drill down on the cause.
Traces, etc.
"Real life" varies with the corporate culture .
- Has no focus on real-time performance monitoring and troubleshooting.
> I was disappointed when the class had not even addressed it. In real
> life, you must be able to decide on some tools that allows you to look
> at a DB real-time and be able to spot an issue immediately. This is the
> most critical of all. This class will not prepare you for this. This is
> what I do almost every day.
Personally I would disagree with that.
Real time monitoring? I've tried it, seemed like a waste of time.
Nice way to keep busy for a few months I guess, while you fine tune the
alarms so that you aren't paged for every little thing that happens.
Maybe we just have a really simple environment, or our users have low
expectations.
Or maybe as Jonathan would say, I'm just lucky, but we rarely have database
performance problems.
Occasionally we do however, but not often. And then it is an issue with the
app. ;)
Monitoring here consists of:
Is the database up? ( this means can I connect to it from a remote client)
Are any jobs hung or broken?
Any interesting errors in the alert.log?
Any db/objects running out of storage space?
Are any passwords going to expire?
Can backups be restored to a recent date?
Did any backups fail?
I suspect that many shops have similar monitoring standards.
- This class will not prepare you for necessary tools and knowledge to
> able to research and report on a DB performance historically. This is
> again very critical for me. What tools can I use to be able to do this.
> Furthermore, I'm asked repeatedly by upper management to provide such
> reports on periodically basis. This class will not help you in this
> regard.
Corporate culture again. Do you think those managers actually read and
understand those reports? Betcha lunch they don't.
But then Hotsos makes no pretense of using Method-R to teach you to create
reports and charts from statspack/AWR data.
- Class focuses at least by 80% of its time on the method itself. Little
> emphasis is put on Oracle internals which are mandatory to understand
> performance. Also, I did not think enough emphasis was put on the
> resolution part and how these measure will work to resolve the issue.
Understanding internals is mandatory to understand performance?
You're read Tom Kyte, right? How often do you seem him delve into
internals?
Have you noticed that he nearly *always* uses simple SQL to prove how to
make Oracle perform?
IMHO, the HS M-R class, is an advanced class that I will not recommend
> as an initial step. I think this method worked great for HS group due to
> the nature and magnitude of problems they get consulted for.
Again I would disagree. Why not learn good methods right from the
beginning?
At that
> level of consulting and visibility, all the necessary pre-requisite work
> is probably have been done for them.
In their dreams maybe.
--
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist
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