Problem Statement


AIXM Feature identification (UUID)

  • The AIXM 5.1 schema relies on the use of Universally Unique Identifiers (UUID) as artificial identifiers for AIXM features.
  • Several algorithms may be used for the generation of the UUID value.
  • A UUID is a 128-bit number that is encoded with a random number displayed as a sequence of 32 hexadecimal digits grouped into a sequence of 8, 4, 4, 4 and 12 digits.

UUID_example_1

UUID Issues

  • A UUID identifies the data that a system stores about a feature.
  • The UUID does not identify a feature!
  • It is therefore possible that two or more data sets exists for the same AIXM feature, in two different systems, with different UUIDs.
  • When data from different sources is merged in a single system, the owner of that system might be confronted with the need to identify and merge duplicate feature data, based on actual properties of the feature, not on the UUID.
Example: WASHINGTON DULLES INTL

The same airport may have different UUIDs in different systems.

How to identify that it is the same feature provided by different systems?

UUID_ISSUE_IAD

 Solution

  • Natural Key is formed of attributes that already exist in the real world.
  • Issue: What to use as Natural Key? In AIXM 5 all feature attributes are optional!
  • Minimum Set of Business Rules needed to ensure Natural Key can be used for unique feature identification.
  • E.g: Airport Heliport has to have a designator.