Yeah, the Java dependency makes me reject it instantly - the only advantage they potentially could have over "just" using any database with ability to query remote databases is not having to roll your own, but the barrier to rolling my own is lower for me than introducing a Java dependency.
(A replicated set of databases for the depots; a set of workers creating the "p-stores" in ... another set of databases, and you've replicated the architecture; heck you can even run this entirely off postgres w/replication + triggers to handle partitioning and materialization with no external workers if you like)
EDIT: Also their API fairly unambiguously is effectively a DSL, just one without it's own separate syntax and parser allowing access from outside the JVM.
(A replicated set of databases for the depots; a set of workers creating the "p-stores" in ... another set of databases, and you've replicated the architecture; heck you can even run this entirely off postgres w/replication + triggers to handle partitioning and materialization with no external workers if you like)
EDIT: Also their API fairly unambiguously is effectively a DSL, just one without it's own separate syntax and parser allowing access from outside the JVM.