Use variable records, if you don't know for sure how long a record could be. There is a 4 byte per record overhead, but who really cares. On Mar 4, 2016 11:14 AM, "Bill Woodger" <[email protected]> wrote:
> Well, the original LRECL is 304. Let's say every record is 300 bytes. > Fills up the block, writes it. No room on the track for the next block. > Next block will be on a different track. Wasteful. > > I mention it because these days it seems that many people (short on > experience) think "I've got a lot of data, what's the maximum record-size I > can use", so they reach for a manual, discover, and happily "design" their > file to have 32000+byte records. > > Yes, I have no clue if "waste" occurs on the underlying physical media, > but that's not the point. Or is it? I don't know. > > I'd like to know if it doesn't matter, as then I can stop raising it every > time I see it. Or can I? When I get to thinking of VSAM, things go Klunk! > again. Or do they...? > > > On Friday, 4 March 2016 14:56:31 UTC, Paul Gilmartin wrote: > > On Fri, 4 Mar 2016 04:58:45 -0600, Bill Woodger wrote: > > > > >Wouldn't that be a little wasteful? One block per track. > > > > > >On Friday, 4 March 2016 10:48:40 UTC, Steve Coalbran wrote: > > >> ALLOC with VB LRECL=32756 ? > > >> ;-) > > >> > > It depends on how clever QSAM is at using the balance of a block which > > can contain several short records. The worst case is one record per > > track. > > > > It has been discussed here that Binder will write short blocks in order > > to fill a track; QSAM generally will not. > > > > -- gil > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
