Re: Other tree representations in SQL

David Cressey wrote:

> Excuse me for jumping off the train, Carl.
>
> Why couldn't you have achieved the same result you describe
> with a hierarchical database?

I haven't been around long enough to know too much about hierarchical databases and I have never had my hands on such a system, but maybe you could educate me a little bit:

• Could you please provide an example, how to query for the "parent" of a "node" in a hierarchical database?
• Can you provide an example how to traverse nodes (segments) in a hierarchical database and how to do something with the data?
• Are there hierarchical databases that provide very tight language bindings to modern object oriented languages like Java? It would be nice to create objects automatically from hierarchical database segments and vice-versa, so one would not have to do that by hand.
• How do hierarchical databases respond to modifications of class model / data schema? Is there a mechanism to manage this automatically for me?
• Can I execute server side code on a hierarchical database?
• I want to be notified of events that happen. Is it difficult to be notified when an object is committed by another user?
• I code with Java or C#. Can I call back into my code, during query execution to perform my own checks. Is this possible with a hierarchical database?
• My Java objects are structured in networks and they recursively link back to themselves. Is it possible to store these kind of network models with hierarchical databases?

...I could go on for an hour with further questions...

The elegance of the code that I posted:

It uses the existing status quo programming language and adds as little as possible additional concepts.

Attempted goals:
- the fastest learning curve

• the least amount of code for any one task
• best possible syntax checking
• best possible refactoring
• maximimum performance by direct pointers
• maximum performance by reducing conversions between languages.

I have no problem, if you want to drive your own train on a different rail, Casey Jones.

Kind regards,
Carl

--
Carl Rosenberger
db4o - database for objects - http://www.db4o.com