Place-Location Meta Model
The Place-Location Meta Model supports administrative attributes, such as the local postal code. The model is designed around two core concepts:
- Place: Describes the human and physical characteristics of a location.
- Location: Describes the physical position and extent of a place. There are two important aspects to location:
- Accessibility: Information on how to get to the location (Accessor).
- Addressability: A textual description of the location according to some regional conventions (Address).
The concepts of Place and Location are interdependent. However, they are represented as two independent entities for the following reasons:
- Lifetime: Places change relatively often, while locations normally remain. For example, shops come and go, but their buildings usually remain.
- Locations without Places: Sometimes there is information about a location that has no associated Place. For example, there are point addresses which do not have an associated Place.
- Places sharing Locations: Multiple places may be associated with the same location.
The messages and approximate relationships are shown in the following logical ER diagram. Only Place and Location are true entities with proper identifiers, while other messages are value objects only. This diagram is provided for illustrative purposes only. The schema messages themselves are the final authority.
The following layers implement the Place-Location Meta Model:
- Places layers
- Administrative Areas & Postal layers
- Cartography Layer
- Buildings layers
