I have been using NReco which provides "C# in-memory OLAP cube for fast data aggregation and pivot reports generation" for a little while now.
The goal now is to port the application to Java. What I am looking for is to:
Add an OLAP layer on top of PostgreSQL so that I can build cubes out of flattened data and
Query the OLAP cube with MDX via my own RESTful API
What do you recommend?