Cassandra - Primary Key

About

This page talks about the primary key of a cassandra table.

The primary key is composed of:

• in first position: the partition keys columns that defines the data location and partition
• in successive position: the clustering columns that defines uniqueness and sort order

If you’re searching by an attribute, this attribute should be a part of the primary key

Example

Example of a primary with:

• the partition key columns channel_id, bucket
• the clustering column message_id. The message id is unique.

CREATE TABLE messages (
   channel_id bigint,
   bucket int,
   message_id bigint,
   author_id bigint,
   content text,
   PRIMARY KEY ((channel_id, bucket), message_id)
) WITH CLUSTERING ORDER BY (message_id DESC);