RE: Sorting a user space

["Bob Cozzi" <cozzi@xxxxxxxxx>]

Rob,
In a nutshell...
QSORT is much faster than the SORTA opcode--provided your compare routine
(call back) is efficient.
The QlgSort and QlgSRTIO APIs may be faster than QSORT but I'm not sure that
the extra complexity is what you want.


-Bob Cozzi
www.RPGxTools.com
RPG xTools - Enjoy programming again.


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx]
On Behalf Of Rick.Chevalier@xxxxxxxxxxxxxxx
Sent: Tuesday, September 13, 2005 1:49 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: RE: Sorting a user space


Rob,

It may be a matter of preference but I would suggest using QSORT. 

I recently wrote an application with a subfile of customer payment history.
Some of the history runs into hundreds of records.  The subfile can be
sorted on any of about five different columns.  I'm not sure if I even
figured out how to solve it using an array and a user index would have to be
rebuilt for every sort.  The way I handled it is when the subfile is loaded
I also load each record into a user space.  When the user requests a sort a
procedure determines which column to sort on and calls QSORT.  There is an
additional procedure to handle the actual high, low, equal logic for QSORT.
The entries are then read from the user space back into the subfile.  Very
fast and simple.

If you are only sorting on one value the array approach would work just
fine.  I'm now a believer in using QSORT when there could be varying sort
criteria.

Rick

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx]On Behalf Of rob@xxxxxxxxx
Sent: Tuesday, September 13, 2005 1:34 PM
To: RPG programming on the AS400 / iSeries
Subject: RE: Sorting a user space


I don't see how that would be any easier, or more effective.

Rob Berendt
--
Group Dekko Services, LLC
Dept 01.073
PO Box 2000
Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com


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