Closer, but still no gold-plated cigar. Cataloging a data set means writing metadata into a catalog (a specific type of system data set) to describe the volume(s) on which another data set is allocated.
Allocating a new data set means writing metadata into a VTOC (Volume Table of Contents) on a volume which is to contain the data set. The metadata represents where on that volume the data set is to be found. At this point, there is still no new data within the data set. The process of writing data into the data set does not have a specific name in IBMology, as far as I know. In my opinion, the data set is not fully created until some program begins writing new data onto the tracks which have been previously reserved to hold that new data through the process known as allocation of a new data set. Cataloging a data set can occur when it is allocated or years later. Populating new data into an allocated data set can occur immediately after the data set is allocated as new or years later. I saw an IBM training video in the mid-1970s in which an IBM trainer used the word "tabulation" to mean the act of writing new metadata into a VTOC to describe a new data set. Nobody uses "tabulate" anymore. Unfortunately, the word "allocate" today has more than one meaning. Many use it to mean reserving space on a volume for a new data set (the same as tabulating). But from the viewpoint of JCL or the dynamic allocation SVC, to allocate a data set merely means to construct the system control blocks that allow a program to access that data set, either by reading from it, writing into it, or both. The space on a volume to hold the data set will not be reserved unless the allocation has the parameter "NEW". If the type of allocation is other than NEW, then it is assumed that the data set has already been "tabulated", or had VTOC entries built to describe its whereabouts on the volume. And "creation" of a data is perhaps the most ambiguous term of all. Bill Fairchild Rocket Software -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Scott Ford Sent: Friday, April 08, 2011 1:21 PM To: [email protected] Subject: Re: DATACLASS I realiaze the BR14 doesnt really 'do anything' , but with JCL Shmuel: I realiaze the BR14 doesnt really 'do anything' , but with JCL attached to it with a disp=new,catalog, I assume that an entry is created in the catalog and the actual dataset is created by the allocating program . Correct ? Scott J Ford ________________________________ From: Shmuel Metz (Seymour J.) <[email protected]> To: [email protected] Sent: Fri, April 8, 2011 12:39:38 PM Subject: Re: DATACLASS In <000001cbf379$98b4cfd0$ca1e6f70$@[email protected]>, on 04/05/2011 at 03:09 AM, Ron Hawkins <[email protected]> said: >I'm not so sure. Based on what I think is Shmuel's logic, no JCL >dataset is allocated by a PGM because allocation occurs before PGM >Fetch. The Initiator is a program. It's just not the program in the relevant EXEC statement. -- Shmuel (Seymour J.) Metz, SysProg and JOAT ISO position; see <http://patriot.net/~shmuel/resume/brief.html> We don't care. We don't have to care, we're Congress. (S877: The Shut up and Eat Your spam act of 2003) ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- 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
