I am surprised to find that there don't really appear to be many open source libraries to support this sort of thing. Like for example sqllite in the RDBMS field. There is jbase with it's multi valued fields and so on, but as far as I can tell it is built on top of a relational model which is more OLAP. Whereas I think I am thinking more along the lines of MOLAP.
First, OLAP is actually data-model independent. You're thinking ROLAP (Relational-OLAP. E.g. Star schemas in a relational database).
Second, I'm not sure that a cube (E.g. the structure behind MOLAP) is the wave of the future as there are column-oriented data stores, such as Infobright, that support ROLAP with great performance and compression while still supporting the relational model. In fact, Infobright uses MySQL, so you can even use the same MySQL drivers to access the database.
Casey
