| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: Needing to brush up on my internals -- FTS and DB buffer cache
Richard's hunch is correct: in the context where the statement is made,
the statement is absurd.
In a very fast skim of the article, it looks like there are some other technical inaccuracies as well. For example, there's a statement in the article, where it says "there are times when the database must examine all of the blocks in the RAM cache..." I think this statement, combined with its three following bullet points, is unfortunately incorrect as well. I believe that in each of the three circumstances the author describes, the Oracle kernel doesn't sweep the cache, but only the buffers on the dirty list.
Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
* Nullius in verba *
Upcoming events:
- Performance Diagnosis 101: 5/7 Dallas, 5/18 New Jersey, 6/22
Pittsburgh
- SQL Optimization 101: 4/19 Denver, 5/3 Boston, 5/24 San Diego
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Richard Foote
Sent: Wednesday, April 28, 2004 9:25 AM
To: oracle-l_at_freelists.org
Subject: Re: Needing to brush up on my internals -- FTS and DB buffer
cache
While surfing Google for HP-UX questions, I ran across an Oracle guru
page
that says this:
"Remember, when Oracle performs a full-table scan, the database blocks
are
read directly into the program global area (PGA), bypassing the data
buffer
RAM."
The article doesn't say what version of Oracle the author was
referring to.
Hi Rich,
I've got a horrible feeling I know who the author is ....
Be afraid, be very afraid .
BTW, did the article mention "parallel" reads at all ? It's relevant.
Cheers
Richard
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://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_at_freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Thu Apr 29 2004 - 08:51:11 CDT
 |
 |