Intersection table representing the resolution of a many to many relationship.

pos_on_esrf_s (FSK, M: CHAR VARYING(19))
pos_on_esrf_t (M: CHAR VARYING(16))
other_material_s (FSK, M: CHAR VARYING(19))

other_material.position_on_earth_surface
Specifies the current or former location of this material.
position_on_earth_surface.other_material
Indicates the various materials which are currently or have formerly been associated with this location.
pos_on_esrf_s: Implements a foreign key to a row in one of the tables projected from entity position_on_earth_surface depending on the value of the next column (See below).
pos_on_esrf_t: Defines the name of the referenced table. Possible values are defined in @position_on_earth_surface.
other_material_s: Defines a foreign key to table other_material.