I agree on the EOF, but I question the RLSE.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of Gibney, Dave [000003b5261cfd78-dmarc-requ...@listserv.ua.edu] Sent: Wednesday, May 11, 2022 1:12 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Potential Resource Savings Techniques If SMS-managed and DSORG known, an unopened new allocation will have an EOF set and RLSE will be process. > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of David Spiegel > Sent: Wednesday, May 11, 2022 9:20 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: Potential Resource Savings Techniques > > Hi Paul, > Allocation does allocation and nothing but allocation. > It does not write anything at all. > > Regards, > David > > On 2022-05-11 12:17, Paul Gilmartin wrote: > > On Wed, 11 May 2022 15:53:20 +0000, Farley, Peter x23353 wrote: > > > >> Only if your SYSIN is not DUMMY. When SYSIN for IDCAMS is DUMMY it > does (and can do) nothing at all, rather more expensively in CPU time than > IEFBR14, but still nothing by comparison. > >> > >> Only if you are allocating and using REPRO from a DUMMY to a new > sequential file or an actual DEFINE for a VSAM cluster for instance would > IDCAMS do what you describe. > >> > > Will it not write an end-of-file at the first extent and RLSE all but > > the first allocation unit of SPACE? > > > > (I suspect the OP did not intend his use of "SYSIN".) > > > > In the Bad Old pre-SMS Days, I sometimes relied on a primary > > allocation of 0 to preclude subsequently reading residual data. > > > >> -----Original Message----- > >> From: <David> <Mingee> > >> Sent: Wednesday, May 11, 2022 11:46 AM > >> > >> IDCAMS does an open and close on the new file and writes zero records, > so if RLSE is coded with the SPACE for output file(s) then the unused trks or > cyls > >> Are released. Secondary space will be used if needed when data is > created in the file later. > >> > >> -----Original Message----- > >> From: David Spiegel > >> Sent: Wednesday, May 11, 2022 11:07 AM > >> > >> I do not understand this at all. > >> How does any program differ from IEFBR14 (with respect to > allocation/freeing unused disk space by DD Statement)? > >> > >> Maybe your shop has an Exit or add-on product which does Storage > Management? > >> > >> On 2022-05-11 01:53, <David> <Minge > wrote: > >>> 5. Consider changing IEFBR14 for allocating new files to IDCAMS with > >>> SYSIN DD DUMMY. This will release unused disk space. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
