RE: Optimizing File I-O in RPG IV/ I-Series

Jim,
Often, if the update can be achieved using an SQL statement, you can
take advantage of the performance benefits that SQL offers for large
data sets. But the proof of the pudding is in the eating.

Cheers, Peter 

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Jim Wiant
Sent: Wednesday, 23 November 2005 1:18 p.m.
To: rpg400-l@xxxxxxxxxxxx
Subject: Optimizing File I-O in RPG IV/ I-Series

We have a series of programs that update files for assorted maintenance.
The time these programs are taking is becoming excessive.

In most cases, the RPG code is very simple.

Key     SETLL                   file
Key     READE                   file
        (Do until EOF)
        UPDATE          record
Key     READE                   file
        END DO

I don't see how the code can get might tighter. Is there any reasonable
compiling options/ CL overrides, etc. that could improve such a routine
when it needs to process a large number of records? We're not opposed to
changing code, but if just a few H spec changes and/or compiling options
could gain us a bit of performance, it would help us out.

I've tried a few of the basics (OPTIMIZE(*FULL), NoDEBUGIO, etc.) but
didn't see much of a change in my benchmarks.

Thanks for any help

Jim Wiant


Once a job is fouled up, anything done to improve it makes it worse. 
Finagle 


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