On Mon, 21 Jan 2013 14:16:23 -0800, retired mainframer wrote: >Did you try it and see it works or if the limitation in the manual is >correct? > Good idea, of course. I've tried it now. That much is true. >:>: -----Original Message----- >:>: Behalf Of Paul Gilmartin >:>: Sent: Monday, January 21, 2013 9:58 AM >:>: >:>: From the description of the ALLOCATE command in the TSO/E >:>: Commands manal: >:>: >:>: REUSE >:>: specifies the file name being allocated is to be freed and reallocated >:>: if it is currently in use. >:>: >:>: When you allocate a data set with file name or ddname, give it a >disposition >:>: of SHR or OLD. You cannot use the REUSE operand to reallocate a file >from >:>: a disposition of OLD to a disposition of SHR. However, you can first >free the >:>: file with a disposition of OLD, then reallocate it with a disposition >of SHR. >:>: >:>: How can [that] restriction be? It seems that if the file is first FREEd, >the ENQ is >:>: removed and reallocating SHR should just work. What's going on here >:>: that they're not telling me. >:>: >:>: It seems that the first paragraph is somehow incorrect and a RCF is in >:>: order. > Lots of other stuff I can put in my putative RCF:
The suggestion to free and allocate with SHR should be accompanied by a caution that this may allow another job, waiting on an ENQ to gain control and the allocate may fail with DATA SET IN USE. The instruction to use SHR or OLD implies that NEW and MOD are mutually exclusive with REUSE. But I'm sure I've used NEW REUSE. Is there really such a restriction? The restriction states that a prior disposition of OLD may not be converted to SHR. But it says nothing about NEW or MOD. May I safely assume, then, that a prior disposition of NEW or MOD will sucessfully be converted to SHR? If the prior disposition is MOD and I specify SHR REUSE, does the disposition become SHR, does it remain MOD, or is it magically converted to OLD? Does the restriction apply only if tne new data set name is the same as the data set name in the prior allocation, or regardless if the names differ? I think I already know the answers to most of these questions or can discover them by experiment (which is a poor substitute for documentation), but the Manual ought also to serve the novice programmer with little experience. All this presumes much familiarity with z/OS concepts and facilities with nary a suggestion how this information may be obtained. I bet Steve C. has some ideas to that end. OK. The TSO/E Command Reference has a "Where to Find More Information", which menions TSO/E User Guide and Information Roadmap (which may mention Using Data Sets). So much background for such an apparently simple command. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
