RE: JDO vs JPA

Hi,

I create Java Data Access Objects to encapsulate the data logic for given
table(s) and use JDBC. I personally do not like the extra complexity of
adding a DB command layer (objects or extensible).

If the files on the AS/400 were created with DDS and a CRTLIB statement then
it is a Library and the files are not Transactional as collections unless
they used commands to create a Data Dictionary (etc) which is not common.

To have Transactionality use the AS/400 SQL command CREATE COLLECTION which
creates the following pieces:
A library: A library groups related objects, and allows you to find objects
by name.
A catalog: A catalog contains descriptions of the tables, views, indexes,
and packages in the collection. A catalog consists of a set of views and if
WITH DATA DICTIONARY is specified, an IDDU data dictionary. For more
information, see the SQL Programming Concepts book.
A journal and journal receiver: A journal QSQJRN and journal receiver
QSQJRN0001 is created in the collection, and is used to record changes to
all tables subsequently created in the collection.

Using this creates a more typical relational SQL database.

Working on a typical AS/400, don't expect the Collection and use DAOs.

Kristen






-----Original Message-----
From: java400-l-bounces@xxxxxxxxxxxx [mailto:java400-l-bounces@xxxxxxxxxxxx]
On Behalf Of MANUEL FIDALGO SICILIA
Sent: Friday, August 19, 2011 3:35 AM
To: java400-l@xxxxxxxxxxxx
Subject: JDO vs JPA

Dear all,

Foremost, I would like to say that I'm new to the AS/400 world so sorry
if I ask stupid things...

At work we are using v6r1m0 and we would to write some Java programs
using the AS/400 as database.

The problem comes when deciding what persistence engine to use: I can't
see clearly if the AS/400 is relational or non-relational and I would
like to know which should be better JPA or JDO. I know some people use
JPA but I'm wondering if it is not better to use JDO which has support
for both relational and non-relational and if JPA will have performance
problems because it is made for relational.

So what do you think? JDO or JPA? Or maybe just jdbc!

Thanks in advance!



Jose Manuel