You are correct in both points below, although if the data set is multivolume you've got a lot of extra work.
But if you have $15K lying around (at least back in the late 1990's), there is the DFSMS Advanced Customization guide, which describes the VVAS service and GETATTR service of FAMS. GETATTR works seamlessly with multi-volume data sets, IIRC. Later, Ray > -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[EMAIL PROTECTED] On Behalf Of Charles Mills > Sent: Wednesday November 16 2005 07:24 > > I'm sure this has been around before but I couldn't find > anything useful searching the archives. > > I know that determining the size of and/or requested size > information for a conventional > non-necessarily-extended-format MVS dataset is an imperfect > science. What is the best option (other than reading it start > to finish!)? > What are the alternatives? > > - Using OBTAIN/CAMLST to read the DSCBs. This gives both > SPACE= information and actual extent sizes. Any comments? > > - I assume that RDJFCB for a not-yet-opened dataset will give > SPACE= information only as coded in the DD statement (or SVC > 99) which would be atypical and/or misleading for input > datasets. Is that correct? The OPEN processing documentation > describes DFSMS as merging the data from the DSCBs into the > JFCB. How is that information available to an application program? > In some way during an OPEN exit? By using RDJFCB after the > dataset has been opened? Or ...? ---------------------------------------------------------------------- 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
