This is a single process executing PDML - As you guessed, the problem arises where an update causes a migration into the top block on the free list - every PX slave is updating a different range, but they might all migrate into the same free block.
Except -- a) Oracle handles this differently on PDML updates to partitioned tables with global indexes: the degree of parallelism in this case is limited to the smallest value for INITRANS found on any of the global indexes. b) If a migration is treated as an insert, then for normal inserts, an absence of freelists results in the next block on the freelist being used anyway. So I can't see why Oracle Corp. has done it this way. (I'm not going to worry about it though, at least for the next couple of weeks - and I'm going to see Steve in Denmark soon, and he may have all the answers by then). Regards Jonathan Lewis http://www.jlcomp.demon.co.uk Coming soon a new one-day tutorial: Cost Based Optimisation (see http://www.jlcomp.demon.co.uk/tutorial.html ) Next Seminar dates: (see http://www.jlcomp.demon.co.uk/seminar.html ) ____England______January 21/23 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]> Date: 29 December 2002 15:45 > >Are you talking about a single process using parallel DML? I guess I could >imagine that even in a case such as a single parallel update setting a >column to a constant. Even though the parallelism would have broken things >up by block ranges, migration could occur into the same block for multiple >processes. > -- 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).
