Taking a different tack - it doesn't really matter very much what the maximum is, as you don't want to have more than 5 concurrent transactions per rollback segment or you start losing space in rollback blocks in a big way. (There is a block reuse pool limited to 5 blocks). And you start getting contention on the segment header undo block if the concurrency goes too high.
Using a formula instead of just looking is perhaps a bit pointless - minor details can change over time, rapidly making the formula incorrect. As the economist said: "Yes, I know it works in practice, but does it work in theory." Jonathan Lewis http://www.jlcomp.demon.co.uk Next Seminar - UK, April 3rd - 5th http://www.jlcomp.demon.co.uk/seminar.html Host to The Co-Operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html Author of: Practical Oracle 8i: Building Efficient Databases -----Original Message----- To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> Date: 07 March 2002 21:25 | |Thanks Robert, and thanks once again, Gopal. | |Now, metalink also has a formula for finding the number of transaction |slots (DOC ID: 177926.999), and Steve Adams too explains precisely how he |arrived at that number of 21 slots for a 2K block size at |http://www.ixora.com.au/q+a/0008/29204045.htm without dumping the header |block, from v$TYPE_SIZE. | |But then the metalink has one formula, if the rollback segment has a fixed |number of extents, and another if it has unlimited number of extents. Steve |Adams also does refer to the extent control headers, but I think he's done |either of the one assumptions. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jonathan Lewis INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- 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).
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