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Physical Reads and Logical Reads

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.

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.


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This was first published in October 2004

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