RE: SQL data access

["Shannon O'Donnell" <shannon.odonnell@xxxxxxxxxxxxxx>]

I'm not familiar with using DDM to access an SQL database such as MySQL.
Is that even possible?  That would be really cool if it is and I will
have learned something new if you could share your solution for how this
works.

What I meant in terms of overhead performance, was that if you have to
add another software package in the middle there, just to create a
pipeline to the SQL database and then format that data into a file that
could be referenced using an F-Spec in an RPG program...that you'd have
a potential application performance issue there because of all the
intervening middleware. 

I didn't think I had to spell it all out. I assumed that list-ees would
be able to reason out the logic on their own. My mistake.


-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Wilt, Charles
Sent: Thursday, October 19, 2006 3:06 PM
To: Midrange Systems Technical Discussion
Subject: RE: SQL data access

> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx 
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Shannon 
> O'Donnell
> Sent: Thursday, October 19, 2006 2:42 PM
> To: Midrange Systems Technical Discussion
> Subject: RE: SQL data access
>
> That would add so much overhead to the performance that I 
> can't imagine
> how it'd be useful. 

Nonsense.  Have you never use a DDM file to access a remote iSeries or
other DB2 database table?

A remote system is a remote system, the problem is that the iSeries
can't talk to anything besides another DRDA database.  Not that it's the
iSeries' fault.  As an open system, the iSeries gets taken advantage of
by all the other proprietary DBs.

> Why not write a procedure you can call from your RPG program that uses
> either:
>
> A java call to perform a jdbc lookup on the table...
>
> Or...
>
> A call to a PC program (maybe a VB program) that does your db lookup?
>
> Or...
>
> An SQL stored procedure you can call on the SQL database?  I 
> assume when
> you say "SQL database" you mean something like MySQL?

Talk about overhead.  I've yet to see an implementation of any of the
above that comes close to the performance of a DDM file between two
iSeries.  Now if IBM would just allow SQL statements over DDM files so
that the iSeries could for instance run a query that joins tables on two
systems.

Charles Wilt
--
iSeries Systems Administrator / Developer
Mitsubishi Electric Automotive America
ph: 513-573-4343
fax: 513-398-1121