On Tue, 01 May 2001 10:36:06 John S. Gage wrote:
>What's the story about this:
>
>http://www.dbxmlgroup.com/
Hi John,
Interesting. Looks a lot like Zope Object Database (ZODB) except the "objects" are
XML and it uses Java rather than Python.
It seems that the open source part is just the XML-ODB part (dbXML Core). It is
unclear how much the application server functions will only be provided through the
commercial product (dbXML Enterprise).
This strategy also parallels Digital Creation's initial plan to deliver ZEO (Zope
Enterprise Object) as the "enterprise" upgrade for its open source ZODB product. Of
course, Digital Creation changed its plan eventually and released ZEO under open
source license.
The weaknesses of dbXML is therefore similar to that of ZODB. There are just so much
already invested in "SQL" legacy code/datastore. Besides, SQL is a good data
manipulation language.
Object databases (dbXML, ZODB etc), in my view, are very useful for storing
object-oriented code/business logic. SQL does not do this well and build-in "triggers"
are problematic as programming languages. Therefore, object databases are superb at
the core of an application server - this is why Zope is so powerful.
At the same time, I think it continues to make sense to write database queries in
SQL and store large datasets in enterprise-proven DBMS like PostgreSQL and SAP-DB.
This is the current strategy of the OIO project: object database (Zope) for source
code storage and SQL database for data storage (PostgreSQL, SAP-DB).
Best regards,
Andrew
---
Andrew P. Ho, M.D.
OIO: Open Infrastructure for Outcomes
TxOutcome.Org (hosting OIO Library #1)
Assistant Clinical Professor
Department of Psychiatry, Harbor-UCLA Medical Center
University of California, Los Angeles
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