[rz2k]

I don't know the answer, but in this case does columnar store imply that it is a collection of arrays, perhaps for a scientific database, and a bit different than HBase?

Here's someone else's blog post from 2010 on different categories of columnar store DBs:

http://dbmsmusings.blogspot.com/2010/03/distinguishing-two-m...

[infinite8s]

That "someone else" is Daniel Abadi, one of the researchers who re-popularized the idea of column stores during his graduate work at MIT (in addition to researchers at CWI).