Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> Log file sync spike

Log file sync spike

From: Laimutis Nedzinskas <Laimutis.Nedzinskas_at_landsbanki.is>
Date: Fri, 9 Jun 2006 16:01:03 -0000
Message-ID: <5A8896FB2AFC5445A7DCFC5903CCA6B02CA269@W03856.li01r1d.lais.net>


I am trying to understand what is causing "log file sync" 5-15 minutes duration spike in my db.
What puzzles me is that I can not see spike in the other activities on my db.

It is strange that:

If "redo synch time" spike happens because of hw problems then why "redo write time" does not follow it?
If it is not hw issue then what else LGWR can be doing 50% of time(see the difference between redo write time and redo synch time) ? Or am I hitting yet another V$-bug?

Database statistics in centiseconds follows:

56,105,687 cs redo synch time from v$sysstat (1.140.674 cs redo synch time from v$sesstat)
54,796,921 cs log file sync from v$system_event

24,163,771 cs redo write time from v$sysstat

162,672 cs log file switch completion from v$system_event

Thank you in advance,
Laimis N.
Fyrirvari/Disclaimer
http://www.landsbanki.is/disclaimer

--
http://www.freelists.org/webpage/oracle-l
Received on Fri Jun 09 2006 - 11:01:03 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US