It’s been a while since I played with #Cassandra. It was pretty enjoyable, but it is hard to wrap one’s mind around schema-less databases.

Remember when you first learned to use random-access files in a programming language? What did you learn? That you had to firmly set a length for each record and which contents which at what locations of each record.

So #MongoDB, Cassandra, and many other databases which use JSON are a big mental challenge just because that makes them so different.