The RDB$INTERRELATIONS system table contains information that
    indicates the interdependencies of objects in the database. The
    RDB$INTERRELATIONS table can be used to determine if an object
    can be dropped or if some other object depends upon its existence
    in the database. The following table provides information on the
    columns of the RDB$INTERRELATIONS system table.

                                Data
    Column Name                 Type      Summary Description

    RDB$OBJECT_NAME             char(31)  The name of the object
                                          that cannot be dropped or
                                          altered because it is used
                                          by some other entity in the
                                          database.
    RDB$SUBOBJECT_NAME          char(31)  The name of the associated
                                          sub-object that cannot be
                                          dropped or altered because
                                          it is used by another
                                          entity in the database.
    RDB$ENTITY_NAME1            char(31)  The name of the entity that
                                          depends on the existence
                                          of the object identified
                                          by the RDB$OBJECT_NAME and
                                          RDB$SUBOBJECT_NAME.
    RDB$ENTITY_NAME2            char(31)  If used, the name of the
                                          entity, together with
                                          RDB$ENTITY_NAME1, that
                                          depends on the existence
                                          of the object specified
                                          in RDB$OBJECT_NAME and
                                          RDB$SUBOBJECT_NAME.
    RDB$USAGE                   char(31)  The relationship among
                                          RDB$OBJECT_NAME,
                                          RDB$SUBOBJECT_NAME,
                                          RDB$ENTITY_NAME1, and
                                          RDB$ENTITY_NAME2.

                                          RDB$USAGE contains a short
                                          description.
    RDB$FLAGS                   integer   Flags.
    RDB$CONSTRAINT_NAME         char(31)  This column is the name
                                          of a constraint that is
                                          referred to from another
                                          system table. The value in
                                          this column equates to a
                                          value for the same column
                                          in the RDB$CONSTRAINTS
                                          system table.
    RDB$SECURITY_CLASS          char(20)  Reserved for future use.