1  –  AS

    Replaces the view select expression and the definitions of the
    columns. The number of expressions in the select list must match
    the original CREATE VIEW column list.

2  –  COMMENT_IS

    Replaces the comment currently defined for the view (if any).
    The comment will be displayed by the SHOW VIEW statement in
    Interactive SQL.

3  –  CONSTRAINT

    Specifies a name for the WITH CHECK OPTION constraint. If you
    omit the name, SQL creates a name. However, Oracle Rdb recommends
    that you always name constraints. If you supply a name for the
    WITH CHECK OPTION constraint, the name must be unique in the
    schema.

    The name for the WITH CHECK OPTION constraint is used by the
    INTEG_FAIL error message when an INSERT or UPDATE statement
    violates the constraint.

4  –  RENAME_TO

    Renames the current view. The new view name must not exist as the
    name of an existing view, table, sequence, or synonym.

5  –  WITH_CHECK_OPTION

    A constraint that places restrictions on update operations made
    to a view. The check option clause ensures that any rows that are
    inserted or updated in a view conform to the definition of the
    view. Do not specify the WITH CHECK OPTION clause with views that
    are read-only.

6  –  WITH_NO_CHECK_OPTION

    Removes any check option constraint currently defined for the
    view.