neovintage by Rimas Silkaitis

Data Modeling in Cassandra from a Postgres Perspective

07 Apr 2016

In my previous post, I introduced some very high level conceptual differences between Postgres and Cassandra. I also refereneced one pattern that I’ve seen where it makes sense to use the two systems together. When you have one very large table in Postgres where the disk size is measured in terabytes, and that’s after it’s been fully vacuumed, it might make sense to bring Cassandra into your architecture. Trust me, that one very large table can create operational headaches over time in Postgres. But how easy is it to model my schema in Cassandra if all I know is Postgres? Cassandra has its own SQL-like dialect called Cassandra Query Language (CQL) that mirrors many of the semantics of SQL but that’s where it stops. You’ll need to know how SQL and CQL differ and how to model the data properly in Cassandra.