RE: Open Access for RPG

I could see an issue with trying to write the handler to deal with a SETLL/READE I/O logic from a typical native IO RPG app. The easy way would be to do nothing with the SETLL (unless there was a result indicator) and then issue a SELECT WHERE TOP 1 sql command for the first READE command and on the next READE a SELECT ??? (not an n SQL expert on how you might get the 2 record). Which could be inefficient depending on the number of rows to get and hardware. Might get tricky to try and use the handler to transfer the read loop into a single SQL command to get a result set and then pass back one record at a time to the RPG app.

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Jon Paris
Sent: Thursday, July 22, 2010 9:57 AM
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: Open Access for RPG

Sorry Charles - I have to completely disagree with you here.

Unless you are performing set updates - not that common - most
business applications still process a retrieved set a row at a time.
Whether that be by retrieving the entire set as an array and then
walking through it, or by using a cursor, or ...

Why can the OAR handler not retrieve the set and then hand it back a
row at a time in response to read requests?

I know it will happen becuase the IBM Lab Services team already do
this with SPECIAL files as part of their database modernization
approach. OAR handlers are a natural and much simpler extension of
that process.


Jon Paris

www.Partner400.com
www.SystemiDeveloper.com



On Jul 22, 2010, at 9:30 AM, rpg400-l-request@xxxxxxxxxxxx wrote:

While you could certainly do it, I doubt it would be a good idea.

The problem is that ROA is designed for RLA and you'd probably need to
use SQL in the handler to access the remote DB. While SQL can
certainly return 1 record at a time, it wouldn't be very efficient.