object-oriented-database

I'm very impressed with my initial tests with db4o. However, i'm wondering just how many enterprise class websites are out there powered by db4o, i couldn't see any on the main website? I can't see any reason why db4o should not be used. There appears to be decent enough support for transactions and ways to handle concurrency for example. Anyone got a list of websites i could look at? See: http://developer.db4o.com/Projects/html/projectspaces/gaabormarkt.html A particular search engine used to be powered by db4o (I say "used to" because I haven't talked to the author about this since a long

I'm looking for information about DB4O object database. I know it has client/server mode, but I have no idea how scalable it is. I'm a big lover of object db idea, but still couldn't find an appropriate OODB to use in any of my projects. So my questions are: I'm interested if anyone deployed DB4O in a multi client environment and how does it perform compared to RDBMS? Is any web app to date powered by DB4O? Can I use DB4O as a replacement for SQL Server (SQL Express at least)? How many concurrent client can DB4O support in practice? Does performance degrades when DB size increases? Thanks P.S.

Please recommend some material about implementing Object-Oriented Databases for dynamic languages (interested in Ruby). I realise that OODBs do not have a good mathematical foundation, but still the information I could find is absolutely insufficient for me to start working on a new OODB. Thanks. Have a look at Won Kim's "Introduction to Object-Oriented Databases" . It's considered an authoritative source on the matter. EDIT: An alternative reference is "Object-Relational Database Development" by Paul Brown . It takes an object/relational approach, which may be interesting given the prevalence

I am working on a small educational project to exercise perst.net. We have a tiny design problem, that is how to best resolve the relation between two classes of objects, that is the participant and championship . It is a many to many relation as participant can take part in many championships and championships can have a multiple participants . Please advise how to do this best in C#, should I use the 'relational DB like' technical class? If you're looking for an object oriented (or domain driven design) approach then a third object to handle the 'join' is entirely the wrong way to go about

I wonder how Object Oriented data modeling is different from Object Relational data modeling? Is it something like the pluses of both object oriented and relational data modeling were clubbed to achieve object relational data modeling? cheers Object-Relational data modeling supports some object-oriented concepts, while still supporting some relational concepts: Inheritance -- one table can have an IS-A relationship with another table. Likewise custom data types support inheritance. Distinction between a class and an object (instance of a class) that goes beyond simply the distinction between a

Is there a database out there that gives you the benefit of referential integrity and being able to use a SQL type language for querying, but also lets entities be loosely defined with respect to their data attributes and also the relationships between them? E.g. take a RBAC type model where you have Permissions, Users, User Groups & Roles. A complex/flexible model could have the following rules: Roles can have one or more permissions and a permission can belong to one or more Roles Users can have one or more permissions and a permission can belong to one or more Users Users Groups can have