Re: Refresh my memory... When are the DSPFD stats reset...

[vhamberg@xxxxxxxxxxx]

Dave

Now THIS is a question I like!!!

There is an article from IBM that explains a lot of these things - the key phrase contained therein is "since last restart", which I assume is IPL.

http://www-912.ibm.com/s_dir/slkbase.NSF/1ac66549a21402188625680b0002037e/5759b9cb5cfc7c2d86256a3e006ae158?OpenDocument

And here's another bit that amplifies on what physical reads and logical reads mean - by Kent Milligan at IBM

http://search400.techtarget.com/expert/KnowledgebaseAnswer/0,289625,sid3_gci1016263_tax299133,00.html?bucket=ETA&topic=299133

QUESTION POSED ON: 15 October 2004 
On the DSPFD listing, what is the difference between Physical Reads and Logical Reads? 
I need to count how may times the file has been accessed. There are no logicals over this file and the file is always accessed by the key on the physical. 
EXPERT RESPONSE
Logical Reads is the number of Logical I/O requests made by DB2 for the physical file (or table). Physical Reads is the actual number of Physical I/O operations performed to satisfy the Logical I/O requests. DB2 might have done a logical I/O request, but there's no physical I/O operation performed because that part of the file was already in memory.
HTH
Vern
-------------- Original message -------------- 
From: "Dave Odom" <Dave.Odom@xxxxxxxxxxxx> 

> especially for Physical Reads? Are they reset at IPL or coming out of 
> restricted state or what? 
>
> Thanks, 
>
> Dave 
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