Cassandra structures tables in rows and columns, just like a relational database. Also like a relational database, the columns available to a table are defined in advance. New columns cannot be added on the fly when inserting data, although it's possible to update an existing table's schema.
Every table defines one or more columns to act as the primary key; each row is uniquely identified by the value(s) in its primary key column(s), and those columns cannot be left blank in any row. Cassandra does not offer auto-incrementing primary keys; each row, when created, must be explicitly assigned a primary key by the client. One good way to structure the primary key is to use a natural key, which is a value that is fundamentally ...
