在Cassandra中，如果将UDT或Collection定义为冻结，则无法更新UDT或collection的单个项目，必须重新插入完整值.

冻结值将多个组件序列化为一个值.非冻结类型允许更新各个字段. Cassandra将冻结类型的值视为blob.整个值都必须被覆盖.

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

来源: https://docs.datastax.com/zh/cql/3.1/cql/cql_reference/collection_type_r.html

@Alon:长话短说:冻结=不变"