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@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of George Leonard Sent: vrijdag 12 maart 2004 13:08 To: oracle-l@xxxxxxxxxxxxx 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@xxxxxxxxxxxxx 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@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Lex de Haan Sent: 12 March 2004 14:04 PM To: oracle-l@xxxxxxxxxxxxx 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@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of George Leonard Sent: vrijdag 12 maart 2004 12:52 To: oracle-l@xxxxxxxxxxxxx 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@xxxxxxxxxxxxx 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 "