Geography Reference
In-Depth Information
5.1.
The DGSD data model.
As shown in figure 5.1, the DGSD tracks administrative entities using
an event-based entity-instance model and associated atributes.
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As Vitit
Kantabutra, J. B. “Jack ” Owens, and their coauthors have recently ex-
plained, a linked entity model is the most efficient structure for historical
spatial data management.
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Its goal is to represent each entity only once
in order to avoid redundancy (multiple records referring to the same
entity) and fragmentation (a single entity incorrectly split into multiple
records). It is also optimized for comprehensive change identification in
order to support our research about frequently changing places. In the
DGSD, as in Kantabutra and Owens's Intentionally Linked Entity (ILE)
model, the entity is a conceptual object that refers to a single place, even
as its spatial, demographic, and political atributes change over time.
Place-making events are recorded in a separate historical instance table
linked to the entity table through explicitly declared relationships. All
named places appear in an entity table. Entities are also linked to atri-
