Re: Marketing the platform was: System i - Mentioned twice in

James Rich wrote:

On Fri, 22 Feb 2008, Joe Pluta wrote:

The options are endless. And I've got demos that show that the basic
architecture flies (at least the J2EE side, and Nathan can attest to the
pure RPG side, although his stuff is proprietary). I'm getting 12 pages
a SECOND on an EGL-based inquiry; it's nearly impossible to match that
in a JDBC environment. But that part of the discussion veers once again
into opinion (which architecture to use).

Joe, can you help me understand the difference between EGL and JDBC? Both are J2EE, correct? I guess I was under the mistaken impression that EGL was simply a rapid development model for doing J2EE apps that use JDBC.

You are correct that both are J2EE. They need a web application server to run, although the goal is to be able to run them on the IAS (Integrated Application Server) that comes with V6R1. And that's where the similarities end.

JDBC is a Java interface to ODBC: basically, a wrapper around SQL. If you're writing JDBC applications, you're writing them in Java. Since JDBC is nothing more than direct access to the data, that means that you have to write all the business logic in Java. Or you can called stored procedures, which can be written in SQL, or you can even, with a little work, invoke ILE RPG programs using the JDBC wrapper. And then you still have to write all the UI logic - you have to learn JSP syntax and HTTP session management and that sort of thing. Adding Ajax or JSF is an additional technology. It's not impossible, and in fact I've taught that part to several companies, but it is an investment.

EGL is a 4GL. You use procedural statements like "get" to fill an array of records. You use a WYSIWYG designer to paint records on JSP pages. The page designer has built-in support for Ajax. The language directly supports invoking ILE programs using a CALL opcode. You don't need any Java or JSF or JavaScript knowledge.

And the EGL team is *very* cognizant of performance issues. As I mentioned, 12 pages per second is pretty darned impressive. That's my train demo - it shows a list of lines in the left pane, and a map of the selected route below it, as well as a list of stations for that line in the right pane. You hold down the next page shortcut, and it flips through the lines 12 times a second, rebuilding the lists and display a different image; it's quite a sight.

Note that I say you don't need any JSF/Java/JavaScript. That doesn't mean that such knowledge won't help! EGL is a true 4GL that generates 3GL code, namely Java, JSF and JavaScript. The more you know about those technologies, the easier it is to understand the generated code when necessary (typically in debugging when something isn't working the way you thought it would). But you can get started on it without that knowledge.

Joe