Undestanding Hibernate Cache Usage Startegy
===


I have cache usage question, I have the following mapping. ST_CD is mapped twice to 2 different properties for whatever reason. Hibernate is throwing 

    org.hibernate.MappingException: Repeated column in mapping for entity: my.package.State column: ST_CD (should be mapped with insert="false" update="false")


I have cache usage as "read-only", so i guess insert and updates are always false; why should I explicitly say insert="false" update="false"?


    <class mutable="false" name="my.package.State" table="STATE_TABLE">
        <cache usage="read-only" />
        <id name="id" column="ST_ID" type="long" />
        <property name="code" type="string" column="ST_CD" />
        <property name="stateAbbreviationCode" type="string" column="ST_CD"/>
        <!- Other properites -->
    </class>