Apache Cassandra Several Partition Keys or Single Computed Key?

2
votes

I am fairly new to Apache Cassandra and one thing I am having a hard time understanding is whether I should have a table with several partition keys or a single computed key (computed in a application layer).

In my specific case I have 16 partition keys k1...k16 that make a single data element unique. With several partition keys I need to provide them in my select statement and I am okay with this, but are there any pros/cons of doing this in terms of storage and or performance?

The way I understand this is the storage might be more, but the partition keys are 'human readable' and potentially queryable by other clients of this data. I assume that cassandra computes some hash on my partition keys whether it's a single value or several.

My question is there storage/performance issues or any other considerations I should think about with having several partition keys or single application computed partition key?

1
cassandraprimary-keycql

1 Answers

3
votes

You are correct, Cassandra converts a multi-part partition key into a single hash. So, I think any efficiencies gains from computing the hash in your application would be minimal at best.

Also, just in case you don't know this, keep in mind that the primary key is divided into the partition key and the clustering keys.

Cheers Ben