On Jul 5, 2006, at 4:04 PM, Charles Mills wrote:
Are you saying that TRUNC is no longer supported?
Charles
Charles,
Not quite sure of that (myself). I would guess it is but of course
there is a different instruction path and you loose some efficiency
if you do do you trunc .
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.
Ed
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED]
On Behalf
Of Ed Gould
Sent: Wednesday, July 05, 2006 12:44 PM
To: [email protected]
Subject: Re: avgrec/avgblk history ?
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.
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