RE: Right-sizing the client (was RE: ODBC (was RE: Green screen - it's time is over ))

> 1)  What is your understanding of the terms?

The definitions have changed over the years.  Originally, a thick client was
one where business logic (including things like database transaction
validation and update) was actually done on the client.  Thin-client
referred to applications where the client code was limited to user
interface, and communicated with a server on the host for any databae
access.

This has changed, as I said earlier.  The advent of the browser ushered in
the concept of the "ultra-thin" client, meaning an application where the
user needed no code other than that which came with the computer (or was
freely available on the Internet).

My personal definition: thick client means applications where custom code
needs to be loaded on the client.  Client Access or a browser is not custom
code.  A Java jar file is custom code.  So, for me a thin client is pretty
much limited to a browser-based application.


> 2)  What are your objections to thick clients?  (Or if you've
> already posted
> them, could you point me in that direction.)

I'm not particularly biased one way or the other, except that thick clients
are much harder to manage.  I've designed both.  If you have a centralized
distribution technique, thick clients can be managed successfully and
provide much better integration with your desktop applications.  A
thin-client (that is, browser-based) application, while easier to manage,
does not provide the same level of integration.  Things like drag and drop
integration to desktop applications simply isn't there.

> 3)  What is your view of a "right-sized" client.  I think this question is
> KEY...

It depends on the situation.  For intranet and even extranet applications
where your user is someone in a predefined group of people over whom you
have some level of control, then a thick client may well be a good solution.
However, this same group may be just as comfortable with a broswer-based
solution, depending on the business requirements.  My work over the last
year or two has proven, at least to me, that HTML can be used as a pure data
entry interface nearly as productive as the standard 5250 we grew up with.

So I guess the only combination I WOULDN'T recommend would be thick client
for Internet applications.  When you have no control over the end user's
configuration, the amount of work required to make your application work on
every possible machine is probably counter-productive, and unless your
application is very mature and stable, the bandwidth required to keep it up
to date might also be prohibitive.

Joe Pluta
www.plutabrothers.com