No wonder I couldn't find it. I was looking under ALTER in DFSMS Access Method Services for Catalogs and could fine no mention of when it would take affect.
On 7/30/2010 at 7:52 AM, in message <[email protected]>, "O'Brien, David W. (NIH/CIT) [C]" <[email protected]> wrote: > Please see 2.5.3.2 Altering the Free Space Specification When Loading a Data > Set in > z/OS V1R11 DFSMS Using Data Sets for a definitive answer. > > The manual does state the file needs to be closed for the new Freespace > values to take effect. > > Thank You, > Dave O'Brien > NIH Contractor > ________________________________________ > From: Thompson, Steve [[email protected]] > Sent: Friday, July 30, 2010 9:41 AM > To: [email protected] > Subject: Re: ALTER of open VSAM cluster > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Joel C. Ewing > Sent: Thursday, July 29, 2010 8:54 PM > To: [email protected] > Subject: Re: ALTER of open VSAM cluster > <SNIPPAGE> > ... > Steve, > If you are implying that changing FREESPACE of a loaded file will affect > future adds at the high end of the key range, this is not true. > Changing FREESPACE has no effect on a VSAM file already containing > records. FREESPACE is only used when the file is in a reset or initial > empty state with no records and an initial file load is done. I am also > certain that if you could ALTER the VSAM catalog entry while the file is > still OPEN for that initial load process, that the running program doing > the load is at that point only using in-memory control blocks for the > VSAM file with values that were derived at OPEN time, and only future > OPENS would see any change. > > <SNIP> > > Unless something has changed since z/OS 1.1, and a third party product > would give new behaviors -- even when not being directly invoked, that > is exactly what we did at a certain insurance type company for their > customer claims file. It was laid down with NO freespace. Then it was > altered pretty much the way I said. The CICS system was brought up after > the ALTER (which is why I said the catalog info was changed -- I didn't > mean to imply an open file would get this behavior without an > intervening close). > > Meanwhile, I was interpreting the original op's question on the basis of > the alter being done for current operations, not later reloading the > file. Yes, in that case the file must be defined with REUSE. > > <SNIP> > > Regards, > Steve Thompson > > ---------------------------------------------------------------------- > 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 >>> The information contained in this electronic communication and any document attached hereto or transmitted herewith is confidential and intended for the exclusive use of the individual or entity named above. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering it to the intended recipient, you are hereby notified that any examination, use, dissemination, distribution or copying of this communication or any part thereof is strictly prohibited. If you have received this communication in error, please immediately notify the sender by reply e-mail and destroy this communication. Thank you. ---------------------------------------------------------------------- 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
