On Mon, 10 Jun 2013 16:02:59 -0500, Paul Gilmartin wrote: >On Mon, 10 Jun 2013 17:43:58 +0000, DASDBILL2 wrote: >> >>Spanned means that a single logical record might span multiple >>physical blocks, but the way it is implemented results in having >>all block sizes be the same, except for possibly the last one, >>which might be short. >> >Do any applications rely on being >able to calculate a cylinder and track address within a VBS data set?
What would that mean, Paul? The records are variable length, so what data would you use to make a calculation? >Is any error reported if an interior block is short? It better not be. >Does this mean >one can't append (MOD) to a VBS data set? Of course not. It is done with SMF data all the time. >What happens if after >writing the last segment of a logical record the block is not filled up >to BLKSIZE but fewer bytes are available than the length of a SDW? Clearly, if a record ends, for example, three bytes short of BLKSIZE, another record cannot be added to that block. The block would have to be written as is, with a block size of three bytes less than BLKSIZE or a program reading it might have errors. At least, that's the way it seems to me. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
