Regards Jonathan Lewis http://www.jlcomp.demon.co.uk http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/seminar.html Optimising Oracle Seminar - schedule updated May 1st ----- Original Message ----- > Take a serious look at two init parameters: > > Optimizer_index_caching > Optimizer_index_cost_adj > > The default values are 0 and 100 respectively which inform the optimizer = > that a) you will never find an index in the buffer cache and b) scanning = > an index is just as expensive as a table. If any of you are familiar = > with Dan Hotka, he recently presented his "Index Advance Tuning" seminar = > at the NOUG DBA SIG here in Boston. His recommendation is to set these = > to 90 and 30(OLTP) or 50(DSS) respectively. I've tried it, it helps and = > does not appear to have any unpleasant side effects. > There is a side-effect to worry about with OICA, especially at low values. see: http://www.dbazine.com/jlewis18.shtml > Dick Goulet > Senior Oracle DBA > Oracle Certified 8i DBA ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------