Paul Gilmartin wrote: <snip>
So the designers committed the unforgivable blunder of failing to differentiate between "0" and "unknown". This has been a problem for me elsewhere, in various DB interfaces, where I want to select all rows in which a certain column is unset, and get, in addition, those in which it is 0, or "", or some other default value.
<snip>
I rather suspect that the original designers of F1DSCBs are long gone, but I think it's perfectly forgivable that in the development time leading up to 1964 their crystal balls might at times have been a bit hazy. After all, the term "computer science" was only three years old in 1964. I actually find it pretty amazing how durable many of these design decisions were. The designers were literally making this stuff up as they went along and had little or no prior experience to guide them.
But, whether we happen to be impressed by their work or not, this particular design choice is what it is, as are many others on which our system's foundations are built. That does not mean we cannot possibly address requirements like this one, however. Perhaps it would be constructive to suggest that DFSMSdss could optionally use DS1CREDT to determine whether a data set with DS1LSTAR set to zero should have its space released. Or, that an "unknown" flag be added to the F9DSCB. Or...
-- John Eells IBM Poughkeepsie ee...@us.ibm.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
