.. change::
    :tags: usecase, postgresql
    :tickets: 7600

    Added compiler support for the PostgreSQL ``NOT VALID`` phrase when rendering
    DDL for the :class:`.CheckConstraint`, :class:`.ForeignKeyConstraint`
    and :class:`.ForeignKey` schema constructs.  Pull request courtesy
    Gilbert Gilb's.

    .. seealso::

        :ref:`postgresql_constraint_options`
