Re: Space Contention and LOG_BUFFER size

From: Connor McDonald <hamcdc_at_yahoo.co.uk>
Date: Wed, 31 Jul 2002 03:13:21 -0800
Message-ID: <F001.004A7135.20020731031321@fatcity.com>

No it does not - but the 'redo log space requests' (imho) is not a good stat for log buffer space sizing, since its common to get this number going up when you switch logs (because briefly everyone is told 'hands off the log buffer').

I prefer the 'log buffer space' wait in
v$system_event, v$session_event. Its rare in "typical" systems for a log buffer over (say) 512-1024k to provide any benefit.

hth
connor

• "Farnsworth, Dave" <DFarnsworth_at_Ashleyfurniture.com> wrote: > I am doing some performance monitoring on an 8.1.7
  > DB on Windoze. I ran the following query;
  >
  > SQL> select name,value
  > 2 from v$sysstat
  > 3 where name = 'redo log space requests';
  >
  > NAME
  > VALUE
  >
  

  ---

  
  > ----------
  > redo log space requests
  > 27
  >
  >
  > If the number of 'redo log space requests' is much
  > over zero then I should increase the LOG_BUFFER size
  > in my init.ora, at least that is what I get from
  > RTFM. One question I have is that does the size of
  > the LOG_BUFFER parameter have to be a multiple of
  > the DB_BLOCK_SIZE parameter? I vaguely remember
  > that it shuold be but have not found anything in TFM
  > to verify this.
  >
  > Thanks,
  >
  > Dave
  > --
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  > Author: Farnsworth, Dave
  > INET: DFarnsworth_at_Ashleyfurniture.com
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Connor McDonald
http://www.oracledba.co.uk
http://www.oaktable.net

"Remember amateurs built the ark - Professionals built the Titanic"

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Received on Wed Jul 31 2002 - 06:13:21 CDT