The failure to do the 90/10 split is a bug (it worked properly in 8.1) which is currently being investigated. I can't remember the number, but I passed it to Oracle some time ago.
As to the original question - no idea, 100/0 seems to be the correct strategy; however, there was an earlier version of Oracle where I did some tests that showed Oracle doing block splits which whose position seemed to be affected by the relative position of the new entry in the block. But I can't find the tests, and I now wonder if it was just the special split to optimise branch compression that Steve Adams worked out a little while ago. Regards Jonathan Lewis http://www.jlcomp.demon.co.uk The educated person is not the person who can answer the questions, but the person who can question the answers -- T. Schick Jr One-day tutorials: http://www.jlcomp.demon.co.uk/tutorial.html Three-day seminar: see http://www.jlcomp.demon.co.uk/seminar.html ____UK___November 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: Wednesday, December 10, 2003 9:24 PM > Hi! > > SQL> select * From v$sysstat where name like '%split%'; > > STATISTIC# NAME > CLASS VALUE > ---------- --------------------------------------------------------------- - > ---------- ---------- > 195 leaf node splits > 128 612 > 196 leaf node 90-10 splits > 128 209 > 197 branch node splits > 128 3 > > I did a little test few days ago (using stats & treedumps): > > If you insert an equal or larger key to the current max value in a full leaf > block *within the transaction which filled the block*, just a new leaf block > is added to index and "leaf node 90-10 splits" statistic is incremented. If > you commit in the meantime, before "overflowing" the block, then the leaf > block is split 50-50 and "leaf node splits" stat is incremented. > So, Oracle 9.2 cares about transactions as well, in addition to checking key > values... > > Tanel. > -- 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).
