I don't advocate doing it for reasons discussed below, but you can mitigate the performance problems (are they even noticeable with modern RAID DASD over FICON) by putting TSO STEPLIBs in LLA/VLF. Likewise for CLIST/REXX libraries if you're willing to put up with...
LLA/VLF members cannot be updated without a corresponding refresh. It's fine to know this in principle, but I've seen programmers get very frustrated trying to update a program or exec without a refresh. The larger the organization, the more chance that someone will overlook this step and waste significant time trying to figure out why their one-line fix is having no effect on the problem they're tackling. An hour of programmer time is hard to recoup a few milliseconds at a time in improved fetch. ;-( . . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 323-715-0595 Mobile 626-543-6132 Office ⇐=== NEW [email protected] -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Tom Conley Sent: Saturday, September 23, 2017 8:11 AM To: [email protected] Subject: (External):Re: Dynamic Steplib and z/OS 2.3? On 9/22/2017 4:55 PM, Walt Farrell wrote: > On Fri, 22 Sep 2017 16:43:43 -0400, Tom Conley <[email protected]> > wrote: > >> Dynamic STEPLIB is designed to run under TSO. It provides the >> ability to satisfy CALL/LINK/ATTACH modules in ISPF for testing, >> multiple releases, etc. Some ill-behaved ISPF apps don't use SELECT >> PGM, so they have to be available in the standard search order. > > You don't need dynamic STEPLIB for that; simply allocate your library to DD > ISPLLIB before you start ISPF, and ISPF will use it as a tasklib for all its > subtasks. It will apply to all module loads, whether they use SELECT PGM or > not. > Walt, The problem with both TSOLIB and ISPLLIB at READY is that those DD's are searched every time you hit enter. They're nearly as bad for performance as STEPLIB in the TSO proc. It also doesn't address when you have to run multiple releases of an ISPF app with CALL/LINK/ATTACH dependencies. With dynamic STEPLIB, you only take the performance hit while you're actually using that app, and you can safely run multiple releases. Regards, Tom Conley ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
