Does the same partition key in different cassandra tables add up to cell theoretical limit?

Question

It is known that a Cassandra partition has a theoretical limit of 2 billion cells. But how does that work in a situation like this one below:

create table ta         


        

Answer 1

Different tables have different partitions. This makes the structure of any particular partition homogenous (it will always follow the proscribed schema of a single table) which allows for optimizations.

If you look at the storage engine under the hood you'll see that every table even has it's own directory structure making it clear that a partition from one table will never interact with the partition of another. (see /var/lib/cassandra/)