On Thu, 20 Aug 2015 11:55:22 -0500 Kirk Wolf <[email protected]> wrote:
:>I'm trying to come up with an efficient way to see if a non-VSAM data set :>has been changed. :>Flipping the DS1IND08 bit is not an option, nor can I install SMF hooks, :>etc in the OS. But can you read SMF? Why these restrictions? Why do you need to know? What if it is changed and then changed back? Is that considered a change? IOW, what is the business case? :>The problem, of course, is that DSCBs don't have "last update timestamps". :>My initial whack at this would be to use a two-part hash: :>part 1: a shortened SHA1-hash of the format-1/8 DSCB :>part 2: a full SHA-1 hash of all of the data :>The goal is to calculate something when I read an entire data set and keep :>it, and then later I can use this to later know if I need to read the data :>again. :>So: a part 1 match is non-informative (the data set could still have :>changed, although not likely) :> a part 1 mismatch would tell me that most probably the data set has :>changed (or just moved?). I would then have to read the entire data set to :>determine if it really has changed. -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
