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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Keep pool
MessageOK -- so it is all about avoiding row chaining... I think I would
still try to choose one block size for your database, and take some chaining
for granted. the problem with multiple block sizes is that you have to
segment your available SGA memory, resulting in less efficiency and more
maintenance. It is a great feature, but it was never intended as a
performance feature, although the thought may seem appealing. It is meant to
open up transportable tablespaces possibilities.
are the rows of these wide tables all fixed length? and are all columns defined as NOT NULL? maybe the 8KB block size would be good enough ... and the advantages of a single block size would outweigh the disadvantages of some chaining. after all, reading a single 16 KB block is not that much cheaper than reading two 8 KB blocks, certainly not when part of a multi-block I/O scan ...
cheers,
Lex.
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of George Leonard
Sent: vrijdag 12 maart 2004 13:08
To: oracle-l_at_freelists.org
Subject: RE: Keep pool
hi there
firstly the database was created as a 8k block size, I have always found
this a very good block size to use.
but I do have some very wide tables and I mean very wide that just ended up better on a 16K block. so I am using /oracle9 feature of mutiple block sizes depended on data requirements.
George
George Leonard
Oracle Database Administrator
Dimension Data (Pty) Ltd
(Reg. No. 1987/006597/07)
Tel: (+27 11) 575 0573
Fax: (+27 11) 576 0573
E-mail:george.leonard_at_za.didata.com
Web: http://www.didata.co.za
You Have The Obligation to Inform One Honestly of the risk, And As a
Person
You Are Committed to Educate Yourself to the Total Risk In Any Activity!
Once Informed & Totally Aware of the Risk,
Every Fool Has the Right to Kill or Injure Themselves as They See Fit!
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Lex de Haan
Sent: 12 March 2004 14:04 PM
To: oracle-l_at_freelists.org
Subject: RE: Keep pool
Hi George,
as far as I know, this is impossible. may I ask why you have two different block sizes in a single database?
kind regards,
Lex.
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of George Leonard
Sent: vrijdag 12 maart 2004 12:52
To: oracle-l_at_freelists.org
Subject: Keep pool
Hi all
I have a mix of 8K and 16K tablespaces.
As such I have configured a 8K and 16K cache pool via:db_cache_size
and
db_16k_cache_size.
I have thus far configured a kep pool via db_keep_cache_size, but I am
guessing this will only be used for the default block size being 8K.
How do I configure (what si the parameter name) for a 16K keep pool ?
thanks
George
________________________________________________
George Leonard
Oracle Database Administrator
Dimension Data (Pty) Ltd
(Reg. No. 1987/006597/07)
Tel: (+27 11) 575 0573
Fax: (+27 11) 576 0573
E-mail:george.leonard_at_za.didata.com
Web: http://www.didata.co.za
You Have The Obligation to Inform One Honestly of the risk, And As a
Person
You Are Committed to Educate Yourself to the Total Risk In Any
Activity!
Once Informed & Totally Aware of the Risk,
Every Fool Has the Right to Kill or Injure Themselves as They See Fit!
This e-mail is sent on the Terms and Conditions that can be accessed
by Clicking on this link http://www.vodacom.net/legal/email.asp "
This e-mail is sent on the Terms and Conditions that can be accessed by
Clicking on this link http://www.vodacom.net/legal/email.asp "
-- 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 Fri Mar 12 2004 - 06:18:57 CST
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