On 2018-01-27, at 13:03:48, Binyamin Dissen wrote: > On Sat, 27 Jan 2018 05:13:36 +0000 Jon Perryman wrote: > > :>On Friday, January 26, 2018 7:05 PM, Paul Gilmartin wrote: > > :>> Paul wrote: Does DCB provide functionality not available via DYNALLOC? > :>DCB is all about the program. There are multiple access methods that can be > used (e.g. bsam, qsam). Each may require different parms and tells > open/read/write how it wants to deal with the file. For example are you > reading sequentially or reading CKD. > > :>DD's (JCL and DYNALLOC) contain information that overrides information in > the DCB. > > Not at all. DCB overrides all. > I believe that the OPEN exit can override options coded in DCB. And, finally, SDB has a chance to fill in a remaining blank.
But I believe there are constructs available in JCL DD that don't exist elsewhere. Referback comes to mind. And I believe there's no way to specify a DSN in a DCB, as is possible with DYNALLOC. -- gil
