Number of writes can be more

Writes in Cassandra aren’t free, but they’re awfully cheap.

Cassandra is optimized for high write throughput, and almost all writes are equally efficient ^[1].

If you can perform extra writes to improve the efficiency of your read queries, it’s almost always a good tradeoff.

Reads tend to be more expensive and are much more difficult to tune.

Denormalization and Data Duplication is Normal

Denormalization and duplication of data is a fact of life with Cassandra. Don’t be afraid of it. Disk space is generally the cheapest resource (compared to CPU, memory, disk IOPs, or network), and Cassandra is architected around that fact. In order to get the most efficient reads, you often need to duplicate data.