On Fri, 29 Nov 2013 17:35:04 -0500, Gerhard Postpischil wrote: >On 11/29/2013 3:00 PM, Paul Gilmartin wrote: >> It should be easy to relax the 8-character maximum (except, >> perhaps on the HLQ) without incompatibility with existing data >> areas, even was done for the antetypical 5-level maximum. > >This could be done except for TSO, due to unfortunate dependences on >both the high and low portion of the data set name. The designers, in >their infinite wisdom, chose to define the PSCB to contain a 7-byte user >id (or user specified prefix), followed by a one byte length. For OS/360 >MVT, the Technion had zaps to get around the limitation (Shmuel may have >a better idea just how many modules they modified). For the last level, >TSO EDIT and possibly other programs, rely on a table of data >characteristics by name (e.g., DATA, CNTL) that also would require changes. > Hmmm. That somewhat proves my point. Under TSO, I was able to allocate a data set with both HLQ and LLQ of 8 characters; edit it (with ISPF) and browse it. I couldn't catalog it because I don't know of an 8-character HLQ to which I have access, but I believe that's an administrative limitation, not anything imposed by the OS. This is a good example of not letting the limitations of one component (TSO) impose a restriction on many others.
And earlier, I neglected to laud IBM for a likewise good decision. Early in the history of Unix System Services, Allocation and JCL were enhanced to support allocating a UNIX pathname to a DDNAME, regardless that a data set so allocated would be unusable by BLDL, STOW, BSAM, QSAM, ATTACH, LINK, STEPLIB, and many others. But doing so opened the way: BLDL (but not STOW or DESERV), BSAM, and QSAM, at least now support data sets allocated to UNIX pathnames. This could not have happened if IBM had chosen to allow the limitations of many components to restrict enhancement of another. I'm eagerly waiting for the support to grow. Bye. Gotta go delete my uncatalogued data set. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
