Prevayler - TRANSPARENT persistence for Java.

9983 TIMES faster than ORACLE.
3251 TIMES faster than MySQL.

I would not believe it if I were you. But I would take a look:
http://www.prevayler.org

Well, I had a look, but I remain to be convinced.

Fundamentally, the strength of the relational database is not speed, but the relational nature of the database (which is mathematically justifiable).

I guess it depends if you only see the database as an object store.

Some people like tables, some people like objects.

Were you at least convinced that Prevayler is an ORDERS OF MAGNITUDE faster and simpler OBJECT persistence mechanism than using ANY relational database for that?

I think that it's a shame you're trying to represent this as a 'replacement' for databases as it looks like a very good product and this just invites people to dismiss it as a silly idea. I (and many other people) don't use a database for pure speed or as an object store. I use a database to make my life easier. The simple fact is relational data is very easy to understand, if you're not a programmer objects generally aren't.
RDBMS' make it very easy to securely share data between different applications.
If my users want to perform an adhoc query on data in a relational database I don't have to get involved .
Also I'm not disputing the recoverability claims, but you don't need to look at many serious database implementations before you see that in the interests of availability etc. people go to ridiculously extreme levels to secure it. When down time costs thousands of dollars every minute you don't much care about how much you need to spend on hardware to achieve redundancy and performance.

Don't get me wrong, I like the look of the product I just think that you're doing yourselves a disservice by claiming it's going to replace an enterprise level RDBMS (maybe it will in the future, but not now).

Having said all that I did download it and will probably use it in the near future.