Re: tough choices

Daniel Morgan wrote:
 >Oracle does not use the word federated to describe any part of its
> architecture and I assumed Microsoft's definition had been stolen from
> DB2.

I may blame Microsft for a lot, but "federated database" is a computer science term. Here is a random link with a definition.

http://www-lsi.upc.es/bloom/home.html

Distributed means roughly that the parts are scattered, but there is one whole DBMS.
Federated means that each part is autonomous. If an Oracle system incorporates data from another, independent Oracle system, then you are facing a federated database setup, whether you or Oracle call it that way or not, any computer science student beyond his introductory databases course will know what it means. The next step is a DBMS that is not only federated, but also heterogeneous. That's where shades of grey come in.
If Oracle and DB2 end up in the same system that could be called heterogeneous (different vendors, different engines). It's more common though to refer to heterogeneity if sources with different models are involved. E.g. DB2 (realtional) accessing Blast (not relational).
IBM is concentrating a lot on that part of the picture with "Garlic" http://portal.acm.org/citation.cfm?id=564751&dl=ACM&coll=portal

Cheers
Serge

-- 
Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab