The DEFINE CONTEXT command creates a context. A context allows
    you to restrict or expand your view of the system and set the
    characteristics associated with your work environment.

    The BASE_PARTITION clause sets the base partition property to
    the partition name you specify. Use the DEFINE PARTITION command
    to create this partition prior to issuing the DEFINE CONTEXT
    command.

    The TOP clause sets the top collection property to the collection
    name you specify. Include this clause only when you are
    redefining the top collection property for an existing context.
    See the DEFINE COLLECTION command for more information on setting
    this property for a new context.

    The DEFAULT_ATTACHMENT clause defines the default attachment
    property for the context. This property refers to the default
    behavior that occurs when you issue the UPDATE command. Choose
    one of the following keywords:

    DEFAULT_
    ATTACHMENT
    Keyword          Behavior

    LATEST           Detaches the version currently attached and
                     attaches the lastest version, whether checked in
                     or ghost.

    LATEST_CHECKIN   Detaches the version currently attached and
                     attaches the version most recently checked in.

    SPECIFIC_        Does not detach the version currently attached.
    VERSION

    If you do not specify the DEFAULT_ATTACHMENT clause, CDO creates
    the context with LATEST default attachment, by default.