#acl YoonKyungKoo:read,write All:read == FAQ == 1. ERROR MESSAGE : Could not perform validation checks for component as the class was not found Turns out that if you are going to use a component as a composite key, the component must 1. Override equals 1. Override hashCode 1. Implement java.io.Serializable 1. ERROR MESSAGE : ORA-00904: "ROLEELEMEN0_"."ID": invalid identifier The HQL was '''delete from RoleElement where role.id = :roleId''' 1. Bulk UPDATE/DELETE cannot include alias * NOTE this issue has been fixed in Hibernate 3.1.x 1. Bulk UPDATE/DELETE cannot include join either explicit or implicit. * above HQL use implicit join in '''role.id''' * you can use sub-queries in the where-clause.