0017 External Identifiers¶
External identifiers are used to correlate the identifiers used in third party metadata catalogs with open metadata elements.
ExternalId entity describes an external identifier from a specific third party metadata repository. It includes:
- The identifier value itself in
The pattern used for the identifier (how it is generated and managed) is stored in
keyPattern. These are the values it can take, with the default (and most used) being
Unique key allocated and used within the scope of a single system.
Key allocated and used within the scope of a single system that is periodically reused for different records.
Key derived from an attribute of the entity, such as email address, passport number.
Key value copied from another system.
Key formed by combining keys from multiple systems.
Key from another system can bey used if system name provided.
Key value will remain active even if records are merged.
Another key pattern.
The mapping of identifiers can be many-to-many, which is why you see that the
ExternalIdLink relationship between the
OpenMetadataRoot (open metadata resources) and the
ExternalId is also many-to-many.
This relationship includes properties to help to map the
OpenMetadataRoot to the external identifier.
There is no guarantee that external identifiers from a third party metadata catalog are globally unique and so the
ExternalIdScope relationship links the external identifier to the
Referenceable that represents the third party metadata catalog. Typically, this is a type of
SoftwareServerCapability, for example,
There is an article on managing external identifiers to correlate metadata elements from different types of technologies.