D ds_Cust DS Qualified Inz
D ARCust 3 Dim( 50000 ) Ascend
D Cust 3p 0 Overlay(ARCust:1)
D Cycle 1a Overlay(AECust:3)
Saludos,
Leonel Mejía Chinchilla
Ingeniero en Software
Gerencia Regional de Tecnología y Operaciones
BAC | Credomatic Network
Tel: (506) 2527-9000 ext.1576 Fax: (506) 2295-9407
email: lmejia@xxxxxxxxxxxxxxxxx
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From: Kurt Anderson <kurt.anderson@xxxxxxxxxxxxxx>
To: "RPG programming on the IBM i / System i (rpg400-l@xxxxxxxxxxxx)"
<rpg400-l@xxxxxxxxxxxx>
Date: 10/11/2011 11:14 a.m.
Subject: %lookup on a Data Structure Array
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
I'm trying to reduce some program I/O for program processing millions of
records. I've identified a file that I feel could be loaded into an array
instead of having the program chain out for every record. Usually this
file is between 100-1000 records. However one of our clients has 20,000
records in the file. So before making the change, I decided to do a
little reading on %lookup, to make sure I'd be using it correctly.
http://www.ibmsystemsmag.com/ibmi/developer/rpg/iSeries-EXTRA--Look-Before-You--Lookup/
It turns out that I had misunderstood how to trigger the binary search
with a %lookup. I thought sorting the array was enough, however to get
the binary search one needs to explicitly specify Ascend or Descend on the
array.
So I went to add Ascend to a data structure array, and it won't let me:
D ds_Cust DS Qualified Inz Dim( 50000 ) Ascend
D Cust 3p 0
D Cycle 1a
Error: RNF3501E Keyword is not allowed for a data-structure definition;
keyword is ignored.
I tried adding the Ascend keyword to the subfield that I use in the
lookup, but it doesn't like that either (I wasn't expecting this to work,
but at this point I'm grasping at straws).
I suppose I could make these two fields their own arrays. Though I'm not
really a fan of that. I love using data structures to group like-data
together.
Is there any way to get the new data structure array lookups to use a
binary search?
Kurt Anderson
Sr. Programmer/Analyst
CustomCall Data Systems
midrange.com
