On Jul 6, 2006, at 1:39 PM, Paul Gilmartin wrote:
On Thu, 6 Jul 2006 12:58:50 -0500, Ed Gould <[EMAIL PROTECTED]>
wrote:
The SAMe SU (IIRC) assumed that all blocks would be the same size
except for the last. I don't recall of finding short blocks in
any of
the QSAM type datasets sine the SAMe came out. I don't recall of a
programmer ever needing a short block. While there may b e a
few out
there I have never run across them personally.
It has long been possible to create interior short blocks by at
least the following techniques:
o RECFM=V
o DISP=MOD
I doubt that SAMe would have had the influence to change either
of those.
-- gil
Gil,
WHile that is true no programmer I ever ran into, ever trusted
"MOD" . Yes it does work though. The programmers really only use of
mod was in checkpoint restart tape. Even then it was grimaced at.
Back in the "old times" uptime was at best bad (can we say 5
minutes?) so no one really trusted it (MOD).
This is the first I have heard of unreliability of DISP=MOD. Is
that the
consensus of readers here?
Paul,
I said 25 years ago.. sorry if you thought I meant *TODAY* .
Ed
That said, my most frequent uses of MOD are for its collateral
effects:
o Conditionally create a data set in an IEFBR14 step with DISP=
(MOD,CATLG),
then write it in a subsequent step with DISP=OLD.
o Conditionally delete a data set with DISP=(MOD,DELETE).
o DISP=MOD,DSN=HLQ.LLQ(&MEMBER) to prevent overwriting an existing
member.
I've distributed some JCL using this, and about once a year I get
a phone
call about a Sx14 ABEND. Generally, the caller is grateful when
I remind
him he was about to overwrite, and renames the existing member
for backup.
-- gil
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