must be fully implemented:
java.sql.Driver
java.sql.DatabaseMetaData
java.sql.ResultSetMetaData

must be partially implemented:
java.sql.CallableStatement
java.sql.Connection
java.sql.PreparedStatement
java.sql.ResultSet
java.sql.Statement

optional:
java.sql.Array
java.sql.Blob
javax.sql.ConnectionEventListener
javax.sql.ConnectionPoolDataSource
java.sql.Clob
javax.sql.DataSource
javax.sql.PooledConnection
java.sql.Ref
java.sql.SQLData
java.sql.SQLInput
java.sql.SQLOutput
java.sql.Struct
javax.sql.XAConnection
javax.sql.XADataSource