RE: What VvRr was BLOCK(*YES) added?

Umm, Jon was one of the main guys in the language lab in Toronto until 
just a few years ago. I think he would know about this stuff. His wife 
Susan is just as smart as Jon, and she was in the lab also.


Paul Nelson
Arbor Solutions, Inc.
708-670-6978  Cell
pnelson@xxxxxxxxxx

"Always do right. This will gratify some people and astonish the rest." 
Samuel L. Clemens  (Mark Twain)




G Armour <garmour400m@xxxxxxxxx>
Sent by: midrange-l-bounces+pnelson=arbsol.com@xxxxxxxxxxxx
10/01/2003 03:05 PM
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        Subject:        RE: What VvRr was BLOCK(*YES) added?


I defer to wiser, more experienced minds, but if I'm guessing correctly,
the RPG-IV F-spec BLOCK(*YES) functions similarly to the S/36 RPG-II block
length entry which appeared just prior to the record length on the F-spec.
 Does the number 9984 ring a bell with anybody?  (Hint: record length =
256 or 128)  Also had an entry for double buffering and, despite some
howls to the contrary, this worked as advertised.

The caveat to it all was that you could shoot your performance down the
hole if you didn't block wisely (i.e., getting a high percentage of your
records in one I/O operation).

The 9984 clue:  256 * 39 = 9984, the highest 4-digit block length for
record lengths of 256 (or 128 or 64...) allowed in the F-spec:
   FHEADER  IPE F9984 256            DISK

Another relic of S/36 that I miss on AS/400:  The ability to block records
for an update file.  Records would be updated in main memory and not
written until a record requested outside the block *and* updated records
in memory were still accessable by other jobs!

All in all, I'm extremely surprised by Jon's suggestion that RPG-IV's
BLOCK(*YES) dates all the way back to V3R2.  Was everyone sleeping at that
announcement?

GA

--- Jon Paris <Jon.Paris@xxxxxxxxxxxxxx> wrote:
>  >> IIRC, BLOCK(*YES) was available for the first release of the OS for
> the
> System/38. Maybe some of the other greybeards can confirm this.
> 
> Not this version.  I think you are talking about blocking options on
> OVRs or
> something like that.
> 
> This question relates to the F-spec option in RPG IV that allows the
> programmer to specify blocking when RPG would not normally do it (i.e.
> when
> a random access operation like CHAIN exists in the program) It was
> introduced ..... Well it seems to have been V3R2/R6 - although it was
> available in VARPG earlier than that.
> 
> Jon Paris

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