Easy way to store and retrieve objects in Java without using a relational DB? [closed]

Answer 1

NeoDatis looks interesting. It is licensed under the LGPL, so not quite as restrictive as the GLP proper.

Check out their 1 minute tutorial to see if it will work for your needs.

Answer 2

Terracotta provides a highly available, highly scalable persistent to disk object store. You can use it for just this feature alone - or you can use it's breadth of features to implement a fully clustered application - your choice.

Terracotta:

• does not break object identity giving you the most natural programming interface
• does not require Serialization
• clusters (and persists) nearly all Java classes (Maps, Locks, Queues, FutureTask, CyclicBarrier, and more)
• persists objects to disk at memory speeds
• moves only object deltas, giving very high performance

Here's a case study about how gnip uses Terracotta for in-memory persistence - no database. Gnip takes in all of the events on Facebook, Twitter, and the like and produces them for consumers in a normalized fashion. Their current solution is processing in excess of 50,000 messages / second.

It's OSS and has a high degree of integration with many other 3rd party frameworks including Spring and Hibernate.

Answer 3

I guess I have found a sort of answer to my question.

Getting the document-oriented paradigm mindset is no easy task when you have always thought your data in terms of relationships, normalization and joins.

CouchDB seems to fit the bill. It still could act as a key-value store but its great querying capabilities (map/reduce, view collations), concurrency readiness and language-agnostic HTTP access makes it my choice.

Only glitch is having to correclty define and map JSON structures to objects, but I'm confident I will come up with a simple solution for usage with relational models from Java and Scala (and worry about caching later on, as contention is moved away from the database). Terracotta could still be useful but certainly not as with an RDBMS scenario.

Thank you all for your input.