Embedded database for Java supporting partial object updates

Question

I need a free embeddable database for use in a commercial java application. It should support search by secondary indexes, operators AND/OR, results ordering and range queries. I expect high amounts of concurrent reads and writes, where the latter are usually multiple object updates on a small subset of the object's properties (or row columns in SQL).

I have explored Hazelcast and CQEngine, but they don't seem to support such partial updates, ie if I need to update a single property of 1000 objects it will rebuild ALL indexes on all the 1000 objects, instead of updating the index for the changed property only.

I could also explore some relational databases like H2 and SQLite, but the problem there is that the set of columns per table (object's properties) is dynamic, ie can change dynamically at runtime. This would lead to altering the schema and rebuilding the whole table and indexes whenever I need to add/remove columns.

Any suggestions for an embedded db or query engine that meets my needs?

Answer 1

I'm developing a NoSQL database; it's called jsndb ( http://sourceforge.net/projects/jsdbase/ ). It's in alpha stage. Give it a try.