VSAM catalog was released in 1974 in OS/VS2 R2, prior to that the catalog was CVOL (dsname SYSCTLG with BLKSIZE=256 and KEYLEN=8). The SYSRES volume was the primary SYSCTLG but could be linked to CVOL on other volumes. The "new" VSAM catalog in 1974 was a big improvement.
On Fri, May 24, 2024 at 12:32 PM Phil Smith III <li...@akphs.com> wrote: > I'm curious whether any of you old-timers can explain why we have both > VTOCs and catalogs. I'm guessing it comes down to (a) VTOCs > came first and catalogs were added to solve some problem (what?) and/or > (b) catalogs were added to save some I/O and/or memory, back > when a bit of those mattered. But I'd like to understand. Anyone? > > > ---------------------------------------------------------------------- > 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