Two things: 1. I have been told that REPRO is a "good" usage of compressed data -- repeated sequential access of any kind gives good results because each buffer is uncompressed only once. OTOH, nearly random access and compressed are "not good" use of compressed data (i.e., higher CPU utilization due to repeated decompression). My particular application is in the "nearly random" category.
2. I personally can't run any tests of extended/compressed VSAM as you suggest, since I am not a storage admin. I'd love to, but I can't. Getting access to Extended authorization for purposes of a "test" is highly unlikely. Seeing a problem (and a potential solution) and having the permissions to be able to determine if the solution would work are two very different things these days. Peter -----Original Message----- From: O'Brien, David W. (NIH/CIT) [C] [mailto:[EMAIL PROTECTED] Sent: Wednesday, May 09, 2007 11:38 AM To: [email protected] Subject: Re: Measuring Use of BLSR Buffers Peter, That argument (often heard) ignores the CPU savings from reduced physical I/O. Don't believe me? Run your own test. Run 2 Repros against a fairly large VSAM file. Use 1 MB of bufsp for one test, the default for the other, then compare the amount of CPU used for each run. The net of using compressed and SMB is more efficient batch using less cpu. Dave O'Brien This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
