LOG_BUFFER

[khussain]

Can someone give me an idea of the log_buffer size ? Currently we have ours set to 163840.

I know some of the books say that it can be >65536 for busy systems. To me even 160K seems small. Can I make it as large as 64MB - anyone sees any disadvantages to that ???

[marist89]

Check your "redo log space requests" and "redo log space wait time" from v$sysstat. If you have high counts, an increase in log_buffer will help...

[khussain]

So is it OK to make the LOG_BUFFER 32 MB - are there any disadvantages ???

[pwoneill]

Check out

[url]http://www.ixora.com.au/q+a/redo.htm[/url] and
[url]http://www.ixora.com.au/q+a/0010/17075858.htm[/url]

For some material on the subject.

[tamilselvan]

32 MB Log buffer size will not be used at all.
You may change it 2 MB or 3 MB.

[mbaliga]

Hi,

If you increase log buffer then redo log space requests will decrease but then the log file sync will take more time. You can check this out from v$system_event.

You can set the log buffer to 1MB and beyond that it starts acting negatively due to larger log file sync time.

It is better to tune log_simultaneous copies also along with log buffer size to achive good performance.

Baliga