Pretty much I would say. Just want to point out that FBS and VBS are worlds apart. As discussed, the 'S' in VBS is 'spanned'. The 'S' in FBS means 'standard' or some such. This guarantees that the file has no short blocks other than the very last one. A file written 'normally' is usually FBS whether labeled that way or not, but one written to multiple times via DISP=MOD is almost certain to have many short blocks, one for each time the file is closed and then reopened.
I doubt that modern processing really cares, but once upon a time FBS was more efficient than FB to read because I/O routines did not have to check for and handle a short block on every read. . . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 323-715-0595 Mobile 626-543-6132 Office ⇐=== NEW robin...@sce.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Bill Woodger Sent: Thursday, January 05, 2017 4:11 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: (External):Re: IEC141I 013-A8: how to read VS data sets? Paul, For QSAM, there's F/FS/FB/FBS, U, V/VB, VS/VBS that you may see used in a business system (and business systems, in the main, are the reasons for having a Mainframe). All have their specific "it's better in this case to do this". Of these, VS/VBS is the slowest way to read or write records, and the least likely that you will see, and the least "known" to programmers, in business systems. "Slowest" means, for large numbers of records (the usual stuff of Mainframe business systems) "more expensive" and "running longer". Neither of these are good. I've seen you suggest that things would be better with VS/VBS only: can you outline how, please? QSAM has limits. You seem to be unable to accept that. It has the limits it has, not the limits that you think it should have. It ain't gonna change. If for your "more and more mysterious" your point is "why didn't it abend, rather than apparently work, although work other than I wanted", then raise it with IBM. I'm not sure it will get a high priority, because mostly people will be expected to respect the limits. Since you are very much at home with HFS, why don't you use that, and just pretend that it is giving you VS/VBS? Won't that make you happy, and leave everyone else choosing the most effective RECFM for the specific task (or not, as it has been known to happen)? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
