VSAM certainly didn't replace PDS. Too bad they didn't port VAM from TSS. In Eunix there is no catalog of file systems that you can mount.
"Every OS Sucks", Three Dead Trolls in a Baggie <https://genius.com/Three-dead-trolls-in-a-baggie-every-os-sucks-lyrics> -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Paul Gilmartin <0000042bfe9c879d-dmarc-requ...@listserv.ua.edu> Sent: Friday, May 24, 2024 11:02 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: VTOCs vs. catalogs On Thu, 23 May 2024 22:24:06 -0500, Mike Schwab wrote: > >VSAM came from the Future Systems development as a complete >replacement, Lynn Wheeler has posts about that. >It was cut back to be an addition to MVS, then combined with CVOL >catalogs to ICF. > "complete replacement" of what, specifically? I have heard the assertion that VSAM was intended to replace all other access methods: QSAM, BSAM, BPAM, ... I have known an OS partisan to rant hereabouts: The MVS catalog tells the OS exactly where a data set resides, whereas with UNIX the programmer must supply such information to access any file. I believe he was referring to pathnames. I have never felt that hardship. UNIX provides alternative facilities: o Mounted filesystems o Symbolic links o Directory hierarchy o The current working directory o Logical filesystems comprising multiple physical volumes, a technique MVS never mastered, partly because of compatibility constraints with BBCCHHR. It was desigh shortsightedness to expose low-level DASD characteristics to high-level programmers. Beyond that, the MVS namespace is woefully small; another archaic and insuperable compatibility constraint. -- gil ---------------------------------------------------------------------- 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
