Should every table in Cassandra have a partition key?

Question

I am trying to create a Cassandra table where i store the logs for a shop as per the timestamp. I also want to create a query which returns the data in a descending order with respect to the timestamp. If I make my timestamp as the primary key it will be automatically be the partition key as i don't have any other columns as composite primary key.

And in Cassandra we can't do ORDER BY on partition keys. Is there any way that I make my timestamp as primary key and not as partition key (A Cassandra DB without a partition key).

Thanks in advance.

table creation if required :

CREATE TABLE myCass.logs(timestamp timestamp, logs text, PRIMARY KEY (timestamp));

Answer 1

Since you have the timestamp you know the year, month, day. You could use those as your partition key and have the timestamp as a clustering column. In this way you would satisfy also the need for a partition key, you will have a primary key for the data, you could order by on timestamps and you would evenly spread your data across the cluster.

This way of splitting data is called bucketing. Here is some good reading on this subject - Cassandra Time Series Data Modeling For Massive Scale