• I've had a go at producing systems with mapping as well and I must admit done well they are incredibly valuable. They are also really quite difficult to get right.

    We get used to constantly working with records that don't always have a real world equivalent - most financial transactions for instance.

    For georgraphical features though to correctly identify a record you actually need to see a map of its location and for instance see if it has the same boundary as something else.

    Utiliites / land parcels / road and rail.

    In this respect the geographical feature / definition is often the ultimate identity of certain geographic records and so if you don't hold its geographical location it its like holding a record without a primary key - ultimately inaccurate.