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Difference between awr metrics [message #404623] Fri, 22 May 2009 08:44 Go to next message
orausern
Messages: 817
Registered: December 2005
Senior Member
Hi,

I am not clear on what is the difference between buffer Nowait% and buffer hit%. I think buffer no wait means a requested buffer is available without having to wait. and buffer hit means the reqeusted buffer is avaialle. so what is the difference in these two metrics?

Can someone explain it?

Thanks
Re: Difference between awr metrics [message #404629 is a reply to message #404623] Fri, 22 May 2009 09:18 Go to previous messageGo to next message
JRowbottom
Messages: 5933
Registered: June 2006
Location: Sunny North Yorkshire, ho...
Senior Member
Buffer Hit% is the ratio of blocks that were already in the buffer cache to the total number of blocks read - ie the more blocks need to be read in from disk, the lower this %age
Re: Difference between awr metrics [message #404632 is a reply to message #404629] Fri, 22 May 2009 09:29 Go to previous messageGo to next message
orausern
Messages: 817
Registered: December 2005
Senior Member
Thank you, what I amnot clear is conceptually how is it different from buffer nowait%? Also can you explain what are the different types of buffers in oracle?

Thanks
Re: Difference between awr metrics [message #404633 is a reply to message #404623] Fri, 22 May 2009 09:35 Go to previous messageGo to next message
BlackSwan
Messages: 25050
Registered: January 2009
Location: SoCal
Senior Member
http://forums.oracle.com/forums/thread.jspa?threadID=903882&tstart=0
Re: Difference between awr metrics [message #404636 is a reply to message #404633] Fri, 22 May 2009 09:40 Go to previous message
orausern
Messages: 817
Registered: December 2005
Senior Member
its my account only there,I posted the question there but didnt get the clarity.
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