What does HackerNews think of mapdb?
MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap-memory. It is a fast and easy to use embedded Java database engine.
I like the idea, but I'd like to learn about use cases for it.
Otherwise, in Java, MapDB is about as far as I'd be willing to go: https://github.com/jankotek/mapdb/
https://github.com/jankotek/mapdb
Scala was around for a long time, perhaps if I could look at it with fresh eyes now I would consider it, but somehow I always had a feeling that Scala isn't for me. And now as Kotlin gaining momentum I'd rather stick with Kotlin.
I want first class IDE support and straightforwardness in my workhorse languages. For hobby languages I'd rather play with something like Red or Perl 6.
Such an in-memory database seems quite important for productivity, so I will definitely consider this.
Read access could be implemented in a first step, while the semantics would still have to be discussed. I think write access would actually be quite important as well so that you can completely abstract away the sending, receiving and processing of events.
Latency compensation or optimistic UI would be nice to have (for making applications more snappy), but I think this is only the third most important piece.
Maybe one can use "SQLiteOpenHelper" with "name" set to "null" for in-memory storage. Or perhaps some things can be adopted from or based on Minimongo, Realm or MapDB:
http://www.quora.com/How-is-Meteors-client-side-database-imp...