Hello folks,

I'd like to know the advantages of using each of the following class hierarchies (and inside a hierarchy when/why using a certain member instead of another):
1) Query (SQLQuery, NamedQuery, AbstractQueryImpl, SQLQueryImpl)

2) Criteria (CriteriaImpl, CriteriaImpl.Subcriteria).

Also is there a difference in term of performance when using a named query (defined in a mapping file: <sql-query ...>, and called by getNamedQuery(String queryName)) instead of a query created by createQuery(String queryString) or createSQLQuery(String queryString).

Thanks.