You gotta imagine the British accent with it Jared. It's what you need to take into account when a database is accessible over the Internet (otherwise known as the "Hacking Factor") ;)
Pete "Controlling developers is like herding cats." Kevin Loney, Oracle DBA Handbook "Oh no, it's not. It's much harder than that!" Bruce Pihlamae, long-term Oracle DBA -----Original Message----- [EMAIL PROTECTED] Sent: Monday, March 24, 2003 3:34 PM To: Multiple recipients of list ORACLE-L Jonathan, What is the 'Haken' factor? Jared "Jonathan Lewis" <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] 03/24/2003 02:24 PM Please respond to ORACLE-L To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> cc: Subject: Re: Reorganizing tables This may have been mentioned already, but a table re-org can be a positive threat to performance. If your primary tables have (for example) a three-stage life: initial row size is small row grows after a couple of weeks row reaches full size after another 4 weeks, then what value are you going to use for your PCTFREE when you rebuild ? If you set it to zero to avoid wasting space for the vast percentage of rows that are full size then many incomplete rows will end up migrating. If you set it to match the growth requirement of the newest rows, then you leave lots of empty space in the blocks that hold only old rows. (The optimum storage answer is to set the Hakan factor before moving the table - but that's not a trivial exercise because of a bug whose number I can't remember). Regards Jonathan Lewis http://www.jlcomp.demon.co.uk For one-day tutorials: (see http://www.jlcomp.demon.co.uk/tutorial.html ) ____UK_______April 8th ____UK_______April 22nd ____Denmark May 21-23rd ____USA_(FL)_May 2nd Next dates for the 3-day seminar: (see http://www.jlcomp.demon.co.uk/seminar.html ) ____UK_(Manchester)_May ____Estonia___June (provisional) ____USA_(CA, TX)_August The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: 24 March 2003 20:53 > Thanks Jared, Rachel, Tom, Dick, Prakash, Ron > > Excellent points. Very much appreciated. Unfortunately at this point people > are asking "but have you tested it?". So I need to construct some type of > test that will demonstrate how much effect a reorg will have. After I've > answered that question, then I can move on to some of the other issues that > you mention. I have joked that if the results are strongly positive, they > won't see me much after that because I'll be touring the world selling my > performance solution that never occurred to anyone else. > Our test system is cloned from an RMAN backup of production so the tables > should be close to production. I'm thinking of creating a new table and > copying the contents of a production table into it and then tracing > full-table scans and comparing the results. > > Jared - is there a way to estimate block-level fragmentation? Comparing the > average row length with the number of blocks used? > > Dennis Williams > DBA, 40%OCP, 100% DBA > Lifetouch, Inc. > [EMAIL PROTECTED] -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jonathan Lewis INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Pete Sharman INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).