Migrating from PH to Java / RDBMS

[Robert J.M. Edis]

G'day Jon

Wow, you have a mighty project ahead of you!  Good luck.

I would like to respond to some of the items you mention below. 

-----Original Message-----
From: Jon.Kvisli@lindorffapplications.com
To: powerh-l@sphere.swau.edu
Sent: 8/2/00 5:45 PM
Subject: Migrating from PH to Java / RDBMS


...

>HOWEVER, times are changing: PowerHouse programmers are hard to find,
>new programmers don't want to learn it, 

There are two issues here:  first, as Java is one the MOST in-demand
development tools around, good Java people charge twice as much as good PH
people and are NO easier to find.  Sure there are kids out of college/uni.
around but they have no business sense.  Second, I know of many new
developers who want to learn PowerHouse when it's explained to them
properly.  Most 'new' developers, especially in the 3GL world of C++/Java
haven't got a clue what a 4GL is.

>users wants GUI and "Office-integration", 
GUI is not ALWAYS the best solution; it depends on what the user is trying
to do.  Besides that, both Axiant 3.0 (much better than previous version)
and PowerHouse Web provide GUI interfaces.  Also you can mix Javascript with
PH Web apps.

>customers wants Internet based access, 
PowerHouse Web.

>and managers&salespersonell wants faster development cycles. 
Java will NOT provide a faster development cycle than PH.  In fact it will
probably be longer, especially when using wet-under-the-ears developers.  A
better internet solution for RAD would be ColdFusion rather than Java.  Find
a 4GL type web tool, not a 3GL.

>New technology provides new possibilities, and having used the same
>tecnology for 15 years, we are now facing the fact that we have a huge
>technologygap to catch up with.

Java is based on C and C has been around as long as unix and unix has been
around since WAY before PowerHouse.  Based on product lifetime, Java is the
OLD technology.  But technology alone doesn't make a better business.  It
doesn't matter what technology you use, if the application design doesn't
support the business fully and is not extensible for business changes in the
future, NO *new* tool will help.

>Our company have decided to skip client/server and move directly from
>characterbased PH to n-tier Java based development, application servers
>and Oracle8i on NT/UNIX. Sadly Cognos have not yet moved their 4GL tools
>to the Javaworld. 

I don't know what you mean by that.  What is "the Javaworld"?

>(I regret to say that I do not think Axiant is a very good move to
>client/server either.) Therefore we have chosen tools from other vendors
>for our future development.

Have you taken Axiant 3.0 for a test drive?

>Indepentant of developing tools, we have realized that a move like this
>introduces several new factors:

>- Moving from proprietary HP3000/MPE/ix to "open" NT/UNIX.
Why is NT/UNIX "open"?

>- Moving from non-relational TurboIMAGE to Oracle RDBMS.
BIG job.  Make sure you spend plenty of time to get your data model right as
it will be VERY hard to fix it later.

- Moving from character-based PowerHouse-managed user interface to GUI.
- Moving from sentralized mainframe to 3-tier / n-tier architecture.
> The HP3000 is not a mainframe, it's a mini or app server, just like a big
NT or UNIX box would be.

>- Moving from data- and procedure oriented development to objectoriented
>development process.

You should be looking at SmallTalk, Enfin, Eiffel, ADA for development and
an OO DBMS if youREALLY want to go OO.  C++ and Java (and Oracle 8i) are
wannabes.

>- Moving from batchoriented production to 7x24 hour availability on
>internet 

Then you should NOT be looking at an NT/UNIX with Oracle 8n as a solution.
OpenVMS on an Alpha Server with Oracle Rdb will provide you with TRUE 7x24
availability.  Just ask NorthernLight, AltaVista and Lycos for example.

>- Completly redesigning the databasestructure and application structure
>as a consequence of 15 year "code-errosion".

As I said, BIG job. (but probably well worth it in the end)

>- AND STILL keeping (or improving) our high-level, high-productivity
>programming environment of today.

You will need to set up parallel environments, one to support your existing
system and one to support the 'new world order'.  Very expensive.

>We have concluded that jumping on all these moves simultanously, will
>give our project a very high risk factor, and that the migration process
>must be done in steps, with intermediate technology shifts and product
>deliveries.

Totally agree.

>One scenario is like this:

>Phase 1: Developing Java and internet based access solution to current
>IMAGE data using gateway technology from Oracle. Improving/normalizing
>datastructure in current IMAGE database.

I would install an RDBMS on your HP3000 and use PowerHouse to 'model' you
new data architecture.  Quickly changing PH programs will be much faster
than grappling with a new development tool AND changing the data structures
at the same time.  Get the data right first, then move to Java.  Remember,
IMAGE is a hierarchical DBMS, you can't properly normalise the data using
it.

>Phase 2: Move database from IMAGE to Oracle8i. Do rest of database
>redesign. Keep current PowerHouse programs on HP-3000, but reprogram for
>relational database in Oracle8i on NT/UNIX. Maybe move PH application
>from MPE/ix to UNIX??

Besides the lower licensing costs, what benfit would there be in switching
to unix?  An MPE/iX environement is more stable htan any unix one (except
maybe True64 UNIX on an AlphaServer.

>Phase 3: Rewrite application "chunck by chunck" using Java technology.
>Moving to OO and GUI development.

Skip Java and use ColdFusion or Hotdog Pro instead.  Or a real OO language
like Eiffel.  Java is still 'young' in its development and doesn't provide
many of the robust features a mature language like PH, Oracle Forms, C++,
Delphi and even SmallTalk provide.  For FULL application development I would
wait until the next stage (JDK 3) is available and tested.


Regards,
Blue in Houston, USA
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
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