On 18 May 2009 14:10:36 -0700, in bit.listserv.ibm-main you wrote: >On Mon, 18 May 2009 18:18:20 +0200, Gilbert Saint-Flour wrote: > >>On Monday 18 May 2009 18:04, Paul Gilmartin wrote: >> >>>>What a stupid necessity that programmers have to code BLOCK CONTAINS 0 ! >>>> >>> What happens if the programmer pre-allocates the data set? >>> It's still a stupid necessity, but it might help in dealing with >>> situations where recompilation is impractical. >> >>Well, pre-allocation is not very compatible with HSM, GDG, and a few other > >I believe I understand the concern with GDG. (Actually, >mu understanding of GDG is so rudimentary I'm not qualified >to doubt the concern.) But what of HSM? Why should there >be a problem? Simply preface an IEFBR14 step with attributes >and DISP=(,CATLG) > >>things. So I believe the combination between DISP=(,NEW,CATLG) and BLOCK >> >??? What's the omitted positional subparameter? Primary disposition >NEW, secondary disposition CATLG? > >>CONTAINS 0 is the best choice to solve potential problems. >> >Yah. It should be done by the access method; the application >should be oblivious to the entire blocking process. > >>And believe it or not, but many years ago, I wrote a utility to update >>load-modules and force BLKSIZE=0. I probably only used it only once. >> >By re-linking? I thought that was the only way. (Well, >massive RYO.) > >Is default unblocked an ANSI Standard requirement? (Of course >this doesn't preclude an extension implemented via compiler >option.)
Implementor defined according to Bill Klein. Since COBOL had no way of specifying UNBLOCKED, I suspect that IBM chose the lack of the BLOCK [CONTAINS] clause to mean unblocked. The current handling is confusing because the BLOCK [CONTAINS] clause isn't specified for VSAM which came after the 1968 standard. > >-- gil > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
