Thanks Kirti and Paul for the reply. The instance is up for only 3 days. We know there are very heavy inserts in the database.
Yes, There are high waits for 'buffer busy waits' event in V$SYSTEM_EVENT view. But I didn't see 'buffer busy waits' in V$SESSION_EVENT. I may try to increase the freelist to 12(I don't know whether it helps, anyway we have 12 Java threads insert data into the same table concurrently). Thanks, Chris --- "Deshpande, Kirti" <[EMAIL PROTECTED]> wrote: > How long has the instance been up? > > It appears that the application is trying to read > the same data blocks &/or > more sessions are trying to update the same data > block or the free lists may > need to be set properly to support concurrent > INSERTs. > > So, before changing anything for DBWR process, I > would suggest to check the > top wait events from V$SYSTEM_EVENT view. You may > see high waits for 'buffer > busy wait' event. If so, I would trace it further > using V$SESSION_EVENT and > V$SESSION_WAIT (P1, P2 values) to find out the 'hot' > segment and the file. > You may have to review the pctfree, freelists, > extent sizes etc. to address > 'buffer busy waits'. > > For all you know, it could be just an application > issue in scheduling the > processes properly. > > And to answer your question about setting > DBWR_WRITE_PROCESSES(actually the > parameter is DB_WRITER_PROCESSES) you may want to > check out Note# 97291.1 on > Metalink. It has some good information. > > HTH, > > - Kirti > > > -----Original Message----- > Sent: Tuesday, January 15, 2002 7:16 PM > To: Multiple recipients of list ORACLE-L > > > Hi, gurus: > The database is oracle8.1.7.2.1 on win2k machine > with 1 CPU and two hard drives. When I query > v$waitstat, I got the following: > > CLASS COUNT TIME > ------------------ ---------- ---------- > data block 246901435 132690159 > segment header 4869 8018 > undo block 20986 38476 > undo header 1895 1556 > > seems like I need to set DBWR_WRITE_PROCESSES to a > higher number, what number should I choose, 2 or > bigger? > > Also, what other problems can you see from the last > query, other than we need to add some more RBS? > > Thanks, > > Chris Harvest. > > __________________________________________________ > Do You Yahoo!? > Send FREE video emails in Yahoo! Mail! > http://promo.yahoo.com/videomail/ > -- > Please see the official ORACLE-L FAQ: > http://www.orafaq.com > -- > Author: CC Harvest > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: > (858) 538-5051 > San Diego, California -- Public Internet > access / Mailing Lists > -------------------------------------------------------------------- > 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). > -- > Please see the official ORACLE-L FAQ: > http://www.orafaq.com > -- > Author: Deshpande, Kirti > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: > (858) 538-5051 > San Diego, California -- Public Internet > access / Mailing Lists > -------------------------------------------------------------------- > 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). __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/ -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: CC Harvest INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- 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).
