There could be some interaction. If DBWR needs to write a block for which the most recent changes are in the log buffer but not in the log file, then DBWR posts LGWR to write - and in earlier versions of Oracle DBWR would then wait for LGWR to sync, in later versions DBWR links the buffer to a holding list carries on down it's main write list and comes back later to pick up the spares (I think).
It is possible that this type of cross-over could produce some redo latch pressure in the right circumstances. 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 Next public appearance2: March 2004 Hotsos Symposium - Keynote March 2004 Charlotte NC - OUG Tutorial April 2004 Iceland One-day tutorials: http://www.jlcomp.demon.co.uk/tutorial.html Three-day seminar: see http://www.jlcomp.demon.co.uk/seminar.html ____UK___February 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: Saturday, January 10, 2004 8:29 AM > Since when is redo log writing > performance handled by DB_WRITERS > or DBWR_IO_SLAVES? > > Cheers > Nuno Souto > [EMAIL PROTECTED] > ----- Original Message ----- > > > Now, the Sr DBA here is screaming about the performance since I made the > change, > in particular, he says he's seeing high redo latch contention and redo > log > buffer waits which he says validates his contention that we need to get > back to > using DBWR_IO_SLAVES. > -- 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).
