On Tue, Aug 21, 2018 at 10:40 AM Phil Smith III <[email protected]> wrote:
> John McKown wrote: > > >What I, personally, think would be nice is something which exists, > >somewhat, in z/OS UNIX files. That is "file tagging". In z/OS UNIX you can > >"tag" a file's contents to specify that the text in the file is in a > >particular CCSID (code page). What might be nice would be if every piece > of > >data could, optionally, be "tagged" as having a CCSID for the data inside > >it. Of course, this only works when all the data inside is "textual" and > >not "binary". Anyway, tag the data as being in a particular CCSID. Then > >have a parameter on the DD statement which basically indicates the CCSID > >that the program expects its data to be in. If the data doesn't have a > >"tag", assume CP-037 for historical purposes. If the DD doesn't specify a > >CCSID, assume CP-037 too. So in the default case, the CCSIDs would both be > >CP-037 so no translation would be made. I am assuming that the access > >method would do the translation, using Unicode System Services, and would > >not do a conversion if the CCSIDs were identical. If the CCSIDs don't > >match, then the access method would use the Unicode services to do the > >translation on input & output. I am assuming that all members of a PD > S > > >would be in the same CCSID. I guess this could be extended for individual > >members in a PDSE version "2.1" or something. The tagging would be > >automatic if a file is created using JCL or DYNALLOC by using the CCSID > >specified in the DD or DYNALLOC. Again, defaulting to CP-037 for historic > >purposes. > > >I'm not saying how this "tagging" would be implemented. I don't know if > >there is any room in the VTOC entry for a CCSID. Or if it would require > >something in the VVDS. And the problem remains for "mixed" data where the > >records contain both "binary" and "textual" information. > > That's an intriguing thought. Of course adding metadata like that to z/OS > data sets creates a whole new mess, with "Oh, that application/whatever > doesn't handle the tagging", but once we got there, it sure would make life > simpler! > That's why I want the access method to implement the CCSID conversion, along with "tagging" and a DD parameter so that the application receives the data in the code point it is written to handle. I don't want the application to have to deal with "metadata", but put it on the back of the access method; most likely QSAM and BSAM and maybe even VSAM. Much like DB2 can do some of this. -- Between infinite and short there is a big difference. -- G.H. Gonnet Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
