In a recent note, Charles Mills said: > Date: Wed, 5 Jul 2006 14:04:35 -0700 > > Are you saying that TRUNC is no longer supported? > I believe neither Tom nor Ed was rumoring the untimely demise of TRUNC; merely stating that, unlike Binder, QSAM will not create interior short blocks for the purpose of filling tracks snugly.
(Ed Gould:) > On Jul 5, 2006, at 9:25 AM, Paul Gilmartin wrote: > ---------------------SNIP-------------------------- > >> > > I don't understand "unused space at the end of each block". Surely > > the interblock gap isn't larger by that amount, so the unused space > > must exist within the block. The only way I know this can occur is > > if RECFM=VBS and the block ends with a null segment. I don't believe > > this is commonly done. > > At some time in previous history (pre MVS?) QSAM did allow for short > blocks at anyplace in the dataset (including the last block). UNLESS > it was created with FBS as the recfm=. I *think* that with SAMe it > became standard practice for all blocks (except the last one) to be > "full" (ie the blocksize of the dataset). I believe that today > blocks are written so that the are "filled up" (ie FBS). VBS is > another animal entirely. -- gil -- StorageTek INFORMATION made POWERFUL ---------------------------------------------------------------------- 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
