Syntax options:

       AUTOMATIC AS value-expr
       AUTOMATIC INSERT AS value-expr
       AUTOMATIC UPDATE AS value-expr

    These AUTOMATIC column clauses allow you to store special
    information when data is inserted into a row or a row is updated.
    For example, you can log application-specific information to
    audit activity or provide essential values, such as time stamps
    or unique identifiers for the data.

    The assignment of values to these types of columns is managed by
    Oracle Rdb. The AUTOMATIC INSERT clause can be used to provide
    a complex default for the column when the row is inserted; it
    cannot be changed by an UPDATE statement. The AUTOMATIC UPDATE
    clause can be used to provide an updated value during an UPDATE
    statement. The unqualified AUTOMATIC clause specifies that the
    value expression should be applied during both INSERT and UPDATE
    statements. The column type is derived from the AS value-expr;
    using CAST allows a specific data type to be specified. However,
    this is not required and is rarely necessary.

    You can define an AUTOMATIC INSERT column to automatically
    receive data during an insert operation. The data is stored like
    any other column, but the column is read-only. Because AUTOMATIC
    columns are treated as read-only columns, they cannot appear in
    the column list for an insert operation nor be modified by an
    update operation. AUTOMATIC UPDATE columns can have an associated
    default value that will be used when the row is inserted.