Mastering Apache Cassandra - Second Edition

A brief introduction to a data model

Cassandra has three containers, one within another. The outermost container is keyspace. You can think of keyspace as a database in the RDBMS land. Tables reside under keyspace. A table can be assumed as a relational database table, except it is more flexible. A table is basically a sorted map of sorted maps (refer to the following figure). Each table must have a primary key. This primary key is called row key or partition key. (We will later see that in a CQL table, the row key is the same as the primary key. If the primary key is made up of more than one column, the first component of this composite key is equivalent to the row key). Each partition is associated with a set of cells. Each cell has a name ...