Migrating from PH to Java / RDBMS

[Jon.Kvisli@lindorffapplications.com]

Was: In Support of PowerHouse

Our company are facing a migration of a 15 old, rather large application
from PH/IMAGE to Java/RDBMS plattform, and I would like to hear from others
who have done this or is in the process of doing it. There are many
questions to be asked when stating such a migration, and I would be
interested in discussing them with others.


First I would like to state that I fully support Neil Harvey's positive
description of PowerHouse and recognize our own situation from his
description: Our company have also been using PH on HP3000 with MPE/ix and
TurboImage since 1985. Like Neil, I also feel that PoweHouse have served us
well, it gives us a very "high-level", "high-productivity" RAD, with a
relative low learning treshold. During these 15 year we have not met a
programming task that could not be solved using PH.

HOWEVER, times are changing: PowerHouse programmers are hard to find, new
programmers don't want to learn it, users wants GUI and
"Office-integration", customers wants Internet based access, and
managers&salespersonell wants faster development cycles. 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.

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 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.

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.
- Moving from non-relational TurboIMAGE to Oracle RDBMS.
- Moving from character-based PowerHouse-managed user interface to GUI.
- Moving from sentralized mainframe to 3-tier / n-tier architecture.
- Moving from data- and procedure oriented development to objectoriented
development process.
- Moving from batchoriented production to 7x24 hour availability on
internet
- Completly redesigning the databasestructure and application structure as
a consequence of 15 year "code-errosion".
- AND STILL keeping (or improving) our high-level, high-productivity
programming environment of today.

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.

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.

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??

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


I would be thankfull  for any serious comment / experiences related to this
topic.

Regards from

Jon Kvisli
----------------------------------------------
Principal consultant
Lindorff Applications as
Hellandtunet forsknings- og næringssenter
Postboks 4, 3833 Bø i Telemark
tlf: 35 06 15 71
fax: 35 06 15 01
e-post: jon.kvisli@lindorffapplications.com
www.lindorffapplications.com
----------------------------------------------


= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Subscribe: "subscribe powerh-l" in message body to majordomo@lists.swau.edu
Unsubscribe: "unsubscribe powerh-l" in message to majordomo@lists.swau.edu
This list is closed, thus to post to the list, you must be a subscriber.