RE: XML

In my view, and I agree with you Aaron, XML is great for short bursts of
data. Connecting to FedEx or UPS to track or ship a package, replacing small
EDI transmissions, and exchanging small numbers of records between
heterogeneous applications. 
Storing an entire database in XML or translating and then transmitting a
multi-million record file is NOT what XML was intended to be used for. It
looks to me like it was intended to allow you to ready about a "page" of
data for transmission or to be displayed (via a browser). It does that
wonderfully.
You can tell it is being used for stuff that was never thought of, by the
fact that there are all these other acronyms/technologies being created on
top of XML to help make it do stuff that it can't. 
In every shop I've been in that does EDI, and granted it has only been a
handful, every one of them attempted to replace traditional EDI with XML.
Every one of them went back to traditional EDI. Why? Try receiving tens of
thousands of EDI transactions in XML, parse it, and then dump it into a
"real" database file on the 400.  

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

-----Original Message-----
From: web400-bounces@xxxxxxxxxxxx [mailto:web400-bounces@xxxxxxxxxxxx] On
Behalf Of albartell
Sent: Friday, November 11, 2005 10:34 AM
To: 'Web Enabling the AS400 / iSeries'
Subject: RE: [WEB400] XML

I think XML is great for many things, the bad part is that it is being
implemented faster than network pipes and processors can handle it at speeds
that aren't noticeable.  I guess we will just have to live that for awhile
until connections get faster and machines get better processors.

>but if you move the creation to the iSeries now it's your problem.
Yep, that is the challenge with doing web services with RPG. When you don't
have to go through all of the different things relating to web services
(SOAP processing, schema validation, etc) then web services are actually
quite fast. But alas, with complexity on the .NET/Java end there are a lot
of features to be gained.


Aaron Bartell


-----Original Message-----
From: web400-bounces+albartell=gmail.com@xxxxxxxxxxxx
[mailto:web400-bounces+albartell=gmail.com@xxxxxxxxxxxx] On Behalf Of Walden
H. Leverich
Sent: Friday, November 11, 2005 8:50 AM
To: Web Enabling the AS400 / iSeries
Subject: RE: [WEB400] XML

Aaron,

>Note that adding XML as a db communication layer for a blackbox
application
>is asking for some real overhead issues. 

I don't want to put words in David's mouth, but since I've done something
similar I think I know what he's doing. It's not so much that XML is the
data transport layer as it's the data storage layer on the offline
application. 

Datasets have this marvelous ability to serialize themselves to/from and XML
stream. And since datasets can have multiple tables and even relationships
between the tables you can actually use the dataset as a mini-database. When
you're online load up the dataset from the iSeries and serialize it do a
local file. When offline simply serialize it in from the local file --
instant offline data access. 

My biggest concern with using anything other that the Dataset to serialize
out the XML in the first place is that you've got to get it right. Simple
XML is, um, simple, but throw in several tables, and the relations between
them and suddenly that XML gets rather ugly. It's not that it can't be done
from RPG -- heck XML is just text -- but if you continue to use .NET to
create the XML you're completely isolated from that ugliness, but if you
move the creation to the iSeries now it's your problem.

-Walden


------------
Walden H Leverich III
Tech Software
(516) 627-3800 x11
WaldenL@xxxxxxxxxxxxxxx
http://www.TechSoftInc.com

Quiquid latine dictum sit altum viditur.
(Whatever is said in Latin seems profound.)

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