Ask HS: What is a good OLAP database choice with node.js?

This question was asked over email and I thought a larger audience might want to take a whack at it.

With a business associate, I am trying to develop a financial software that handles financial reports of listed companies. We managed to create this database with all the data necessary to do financial analysis. My associate is a Business Intelligence specialist so he is keen to use OLAPs databases like Microsoft Analysis Services or Jedox Palo, which enables in-memory calculations and very fast aggregation, slicing and dicing of data or write-backs.

At the same time I did an online course (MOOC) from Stanford CS184 called Startup Engineering which promoted/talked a lot about javascript and especially node.js as the language of the future for servers.

As I am keen to use open-source technologies (would be keen to avoid MS SSAS) for the development of a website to access this financial data , and there are so many choices for databases out there (Postgre, MongoDB, MySQL etc..but don't think they have OLAP features), do you know of resources, blogs, people knowledgeable on the matter, which talk about combination of node.js with OLAP databases? best use of a particular system with node.js?

Thanks for your input.