Materialized-View-Mapping

Achilles supports the new Cassandra 3.0 materialized view feature. To mark an entity as
a materialized view, you can use the @MaterializedView annotation.

    @Table(table = "user")
    public class UserEntity {
        ...
    }
    @MaterializedView(baseEntity = UserEntity.class, view = "user_by_country")
    public class UserByCountryView {
    
    }
    

The @MaterializedView annotation defines 3 attributes:

• baseEntity (MANDATORY): the entity class from which this materialized view is derived
• keyspace (OPTIONAL): the name of the keyspace in which this materialized view belongs to
• view (OPTIONAL): the name of the materialized view. Defaults to the short class name if not provided

A materialized view must comply to some rules:

• the materialized view can declare a subset or all of the base entity fields
• each field in the materialized view should match the name, source type and target type of the same field in the base entity
• all base entity primary key fields should be in the materialized view primary key
• all collection and UDT types of the base entity should be duplicated to the materialized view
• a materialized view is allowed to have among its primary key fields maximum 1 field which is not a primary key from the base table

Failing one of these rules will trigger a compilation error.

Furthermore, since only read operations are allowed on a materialized view, the generated manager for the view has a
restricted API:

• crud().findById(...)
• dsl().select()...
• raw().typedQueryForSelect(...)
• raw().nativeQuery(...)

For raw().nativeQuery(...), a runtime check is performed on the provided statement to ensure it is a SELECT statement