PMFJI here, but I cannot hold my (virtual) tongue any longer. ALL of what is being argued about here ASSuMEs that somthing BAD has happened. Either an ABEND or a CICS IMMediate shutdown or some other ABNORMAL event.
ISTM that for the vast majority of programmers who might use those VSAM statistics, there are LONG stretches of time where their VSAM files are JUST FINE, with no abends or other "bad" events to disturb the statistics. In those cases, the stats are just what they say they are, and can reasonably be used to make decisions (like when to reorganize or review performance, etc.). Just because they are not written when something BAD happens is NOT a reason to see them as invalid or useless. Like anything else in this business (or life, for that matter), you need to know what you are talking about when you use statistics to justify a decision. Mark, I think your view might be warped by only getting involved from the IBM side when "something BAD" has already happened to the hapless user. Lighten up guys. It's not that urgent or critical, really. It's only stats, after all. Just my USD$0.02 worth. Peter -----Original Message----- From: Mark Thomen [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 05, 2005 5:41 PM To: [email protected] Subject: Re: IBM VSAM Statistics are often Bogus "Joel C. Ewing" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > I strongly disagree on the desirability of suppressing VSAM statistics > in these cases. It would be much better to display them while > indicating that they are incomplete. > > The delta in the LISTCAT VSAM statistics correctly reflects the activity > to the VSAM data set between two points in time, as long as you compare > between two points where the VSAM file is closed and also know there > are no intervening OPENs without a valid CLOSE. This is extremely > useful as an activity measurement tool, even if the absolute values are > missing counts from earlier accesses. Most people don't do this. They look at the stats and make decisions. They don't look at the "delta" before and after using the data set. As I said earlier, the biggest place where we see the problem are people that do immediate shutdowns of CICS. You load a file with 100K records on Sunday night, and by Saturday night you've done 150K adds, 379K updates, and 75K deletions. Then you do an immediate shutdown and guess what you get? Stats that show 100K records in the file, no updates, no deletes, no splits, no nothing. > > I would hate to see one program ABEND make it impossible to get any > statistics from all VSAM datasets used by the program until those > datasets have been reorganized by unload/reload, as in some cases it may > not be practical to reorganize the files for weeks or months. Sorry, but the stats don't get updated on an ABEND. > > This also suggests that calling the statistics "INVALID" may be too > strong a pejorative, as all the counts reflect actual activity to the > file - it's just that they do not represent ALL the activity to the file. I'm afraid I don't understand how this doesn't make the results "invalid". If your gas gauge says 1/4 tank as your engine coughs and halts, wouldn't you consider your gas gauge registering "invalid"? _ 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
