You need the Oracle Rdb READ and ERASE privileges to the relation
    and the Oracle Rdb ERASE privilege to the database to use the ERASE
    statement.

    You cannot erase records from a view that was formed with one of
    the following clauses:

    o  WITH clause of an RDO record selection expression

    o  REDUCED TO clause of an RDO record selection expression

    o  CROSS clause of an RDO record selection expression

    o  UNION clause of an SQL select expression

    Prior to Version 4.1, Oracle Rdb allowed you to erase rows from a
    table that was directly joined with other tables. Beginning with
    Version 4.1, Oracle Rdb returns an error message if you try to erase
    a row under these conditions. For example, Oracle Rdb will return
    the error, $RDMS-E-JOIN_CTX_UPD, relation EMPLOYEES is part of
    a join, cannot be updated, when you try to execute the following
    query:

    FOR E IN EMPLOYEES CROSS D IN DEGREES OVER EMPLOYEE_ID
        WITH D.DEGREE= 'MA'
        ERASE E
    END_FOR

    In the preceding query, if an employee has two MA degrees, the
    same employee row will be joined to two different degree rows.
    Therefore, Oracle Rdb will try to delete the same row twice. The
    previous update query can be reworded into an equivalent form to
    achieve the desired results as follows:

    FOR E IN EMPLOYEES WITH
       (ANY D IN DEGREES WITH D.EMPLOYEE_ID = E.EMPLOYEE_ID)
       ERASE E
    END_FOR

    The rows can now be erased because the EMPLOYEES table is no
    longer directly joined to the DEGREES table. The use of this
    query guarantees that an employee row will not be deleted more
    than once.

    Note that some examples in the Guide to Using RDO, RDBPRE, and
    RDML will no longer work with the update rules created in Oracle Rdb
    Version 4.1. To run these examples, rewrite them using the ANY
    subquery mentioned previously.