well, I would like to say the OLAP Cube is just re-rising now. There are 1000+ companies deployed Apache Kylin (OLAP Engine for Big Data) in the past 5 years, for 100+B rows, for 100+ concurrent users...many different use cases are based that technology...it works very well with BI tools and so friendly to analysts who are using such "old fashion" every day over the decade (how hard for them to be Data Scientists?) check more here: http://kylin.apache.org/community/poweredby.html