Collection type

A collection column is declared using the collection type, followed by another type, such as int or text, in angle brackets. For example, you can create a table having a list of textual elements, a list of integers, or a list of some other element types.

list<text>
list<int>

Collection types cannot currently be nested. For example, you cannot define a list within a list:

list<list<int>>     // not allowed

In Apache Cassandra™ 2.1 and later, you can create an index on a column of type map, set, or list.

Using frozen in a collection 

A frozen value serializes multiple components into a single value. Non-frozen types allow updates to individual fields. Apache Cassandra™ treats the value of a frozen type as a blob. The entire value must be overwritten.

column_name <collection_type><cql_type, frozen<column_name>>

For example:

CREATE TABLE mykeyspace.users (
  id uuid PRIMARY KEY,
  name frozen <fullname>,
  direct_reports set<frozen <fullname>>,     // a collection set
  addresses map<text, frozen <address>>     // a collection map
);