> I cracked open a (metaphorical) history book, and I discovered that IBM > introduced PDSEs in 1989 -- about 24 years ago as I write this. > > I agree with John Gilmore. A 2013 PDSE prerequisite for Enterprise COBOL > 5.1 is not too soon.
Some customers have already stated in this discussion that they have program library PDS data sets which they share across sysplex boundaries. Unless such a data set is never updated from one sysplex without re-IPLing all of the systems in other sysplexes which might access that data set (or at least restarting the PDSE1 address space, if you use that), then you cannot convert these PDS data sets to PDSEs without exposing yourself to PDSE issues which do not occur in the same way for PDS data sets. This is due to caching which is done at a system level for PDSE, but not PDS. PDSE also does space reclamation differently from PDS, and some customers may have operational procedures which depend on the PDS property that space is not reclaimed until an explicit compress operation is executed. So in some cases, a PDSE is not a plug compatible replacement for a PDS. What is your proposed solution for customers who currently share COBOL PDS libraries across sysplex boundaries? >You can also get acquainted with PDSEs > and their impacts. (Did I actually just write that? :-)) You did indeed write that, and it would suggest that you may be less acquainted with some of the impacts of PDSEs than the experienced z/OS systems programmers on IBM-MAIN. PDSE certainly does have significant advantages over PDS in many environments, but there do remain some situations in which the lack of caching and the more primitive space reclamation characteristics of PDS can be advantageous. And while it is certainly reasonable for COBOL to exploit program object functionality which is not available with load modules, the fact remains that MVS made a decision long ago to tie program objects to PDSE, and thus for some customer environments, moving to COBOL 5.1 may involve operational changes which are more complex than simply converting COBOL program libraries from PDS to PDSE. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
