There are all sorts of things you can do to speed up the process of writing log files:
a) direct io file systems b) isolate logs onto disks c) raw d) faster disks e) ultra fine grain striping f) transaction_auditing = false etc etc etc...but the big key here is: "Each and every record is committed"... bad bad news there...With that policy, you'll almost always be constricted on lgwr performance. Cheers Connor --- Pat Howe <[EMAIL PROTECTED]> wrote: > We have a canned package that we use to insert > approx 100 records/second > into one table (oltp environment). > Each record is just under 1K (datatypes = number and > varchar). > There are several indexes that are build on the > table as the records are > inserted. > Each and every record is committed. > Therefore we are flushing the 'redo log buffer' to > disk (online redo > logfiles) 100 times per second (once per commit). > > Not surprisingly we have noticed IO waits which we > believe are associated > with our 'Redo Log buffer'. Namely ; > log_file_sync = 180 waits/sec > log_file_parallel_write = 180 waits/sec > > We tried resizing the 'redo log buffer' from 16K to > 256K - but we did not > notice any improvements. > Neither Log switching or archiving seem to be > excessive. > 100 records per second seems to be our maximum speed > without the application > queuing up and Oracle showing very high waits on > log_file_sync and > log_file_parallel_writes. > > Does anyone know how we might be able to minimize > the IO waits? > > Thanks in advance. > > ENVIRONMENT > oracle : Oracle 8.1.7.4 > os : Sun Sparc Solaris 8 > box : 8x8 E10K > IO : Hitachi SANS unit through fiber and Brocade > switch > > > _________________________ > Patrick J. Howe > > > > -- > Please see the official ORACLE-L FAQ: > http://www.orafaq.com > -- > Author: Pat Howe > 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). ===== Connor McDonald http://www.oracledba.co.uk http://www.oaktable.net "Remember amateurs built the ark - Professionals built the Titanic" __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: =?iso-8859-1?q?Connor=20McDonald?= 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).
