RE: RPG Blocked Writes

Yes Kurt is correct. On 'Output' (prints) is has no effect. We have never used this on any of our outputs.

William Moore
California Fine Wire
805-489-5144

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Kurt Anderson
Sent: Tuesday, June 08, 2010 11:27 AM
To: rpg400-l@xxxxxxxxxxxx
Subject: RE: RPG Blocked Writes

Interesting, all of our programs have the A on output files, so I never thought twice about it. Then again, what does output with add mean?

So I went to the help about it:
"Position 20 (File Addition). Position 20 indicates whether records are to be added to an input or update file. For output files, this entry is ignored."

Ok, I just ran a test and removing the A from the F-spec did not change the file to start block writing. Looks like IBM's correct. The A there doesn't matter on an output F-spec.

-Kurt

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Jeff Crosby
Sent: Tuesday, June 08, 2010 12:00 PM
To: RPG programming on the IBM i / System i
Subject: Re: RPG Blocked Writes

It's output with ADD.

On Tue, Jun 8, 2010 at 9:44 AM, Kurt Anderson
<kurt.anderson@xxxxxxxxxxxxxx>wrote:

Simon,

FFileA O A E K Disk

You're telling me that's not output only?

And the sentence after the quote I provided is:
"The programmer is expected to override the file or use larger blocks
if the default is not appropriate."
But the default _is_ appropriate. It's an output-only specification,
and thus should block (barring other reasons for the file not blocking
which isn't mentioned in the article).

If it's the K you're referring to in the F-Spec as being an issue, I
tried removing it (per an earlier thread response) to no effect.
Hwoever, even with the K it's still output-only. I see no way I could
read or update that file.

Thanks,

-Kurt


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]
On Behalf Of Simon Coulter
Sent: Monday, June 07, 2010 6:33 PM
To: RPG programming on the IBM i / System i
Subject: Re: RPG Blocked Writes


On 08/06/2010, at 8:22 AM, Kurt Anderson wrote:

I have a file defined in a program as:

FFileA O A E K Disk

From my understanding, writes to this file should be blocked.
However when I look at the I/O for the job, the I/O count and the
RRN is always equal. For comparison, reading a file that's blocked
has a lower I/O count than the current RRN.

Is this a matter of me not understanding the I/O screen (when
looking at the job as it is running), or is this file actually
writing a single record at a time?

According to this document, I feel that these writes should be
blocked.

https://www-912.ibm.com/s_dir/slkbase.NSF/1ac66549a21402188625680b0002
037e/d6738e1cd37e1f33862565c2007cef79?OpenDocument

"All high-level language programs (HLLs) use blocking at certain
times and use single record I/O at other times, based on program
specifications. Because blocking takes less system resources to
perform a single I/O, a program that blocks performs better and uses
less system resources. The default for the HLL uses record blocking
if opening a file for output only (write) or input only (read)."

Read this part again:

"The default for the HLL uses record blocking if opening a file for
output only (write) or input only (read)."

and then compare that with your file specification:

FFileA O A E K Disk

paying particular attention to the use of the word "ONLY" in the
blocking explanation. If that's not clear enough then re-read the
original paragraph (of which you quoted only part)--specifically the
second sentence after the one you think should cause blocking.


Regards,
Simon Coulter.
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Jeff Crosby
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UniPro FoodService/Dilgard
P.O. Box 13369
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260-422-7531
www.dilgardfoods.com

The opinions expressed are my own and not necessarily the opinion of my company. Unless I say so.
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