Does any of you know any database engine that could be in standalone/embedded mode (with zero administratrion) and at the same time could be in client/server mode? In other words, I need the database to be able to run by itself and when required by the enduser, be able to run in client mode where it connects to a remote database.

I looked into mysql embedded but it's still not mature (I spent a day trying to get it to work), although it is exactly what I'm looking for.
I also looked into OLE DB however, the msdn docs are full of concepts and are lacking in "how to's". Moreover, I couldn't seem to find information on how to connect to remote databases (although it stated that it could) and how to create zero-administration datasources.... not to mention I'm still confused by its relation with odbc and such.

Could anybody offer some advice? Or refer me to a good tutorial site on OLE DB?

thanks