Client data isolation: can Cassandra store data in different partitions in separate file sets?

Question

Suppose I have a Cassandra table with an integer partition key.

Question: is it possible to arrange for Cassandra to store the table data and indexes for that table in a sets of files by partition value? Alternative approaches like per partition keyspaces or duplicating tables Account1 (for partition key 1), Account2 (for partition key 2) is deemed to undercut Cassandra performance.

The desired outcome is to reduce the possibility of selecting sensitive client data for partition 1 getting other partitions in the process. If the data is kept separate (and searched separately) this risk is reduced --- obviously not eliminated. Essentially it shifts the responsibility of using the right partition key at the right time somewhat onto Cassandra from the application code.

Answer 1

It's not possible in the Cassandra itself, until you separate data into tables/keyspaces, but as you mentioned - it will lead to bad performance.

DataStax Enterprise (DSE) has functionality called Row Level Access Control that allows you to set permissions based on the value of partition key (or part of partition key).

If you need to stick to plain Cassandra, then you need to do it on the application level.