For a long time I dream someday there could be born a relational database in memory.So we can take advantage of both relational math and high speed in memory.When I find EJB,I believe that's the thing at first.But it's not.I don't think the technology is far from reality.
I also dream someday one new product that combines both relational math and object-oriented thought could occur.
An RDBMS cache achieves this.. also a distributed shared data object cache achieves high-speed long-lived object caching as well. There are several EJB products that offer this.
There is some research in the database field to
try to combine the beauty of relational model and
the object model. Also the object database does
As to the memory-db, I think it is almost impossible. Today the memory-size increases fast but the data-capacity of the
database increases much faster than the memory-size.
Are you the author of Mastering Enterprise Javabeans.If you are,I am so excited.I just download your book and read it which lead me into the world of EJB.
As to oodb,is there any products in application?Jasmine?
OODB's in use: Gemstone/J, Persistence PowerTier (the latter uses an OODB as it's object/relational cache). Both are meant for high-volume applications, such as logistics, operations or trading systems and have an appropriate level of sophistication to meet those needs.
On a smaller note, one can look at an object-relational mapper to have an "in memory" data map. Apple WebObjects does an admirable job of this, as does Cocobase and TOPLink.