Area 0 - Extensions to the base model

In the Atlas build, model files are added in alphanumeric order to build up the type library.  Therefore the model files are numbered to ensure its dependencies have been resolved before a model file is loaded.   For the open metadata types, the model file number is shown in package name to document the intended load order.  The numbering scheme of the metadata areas described in Building out the Apache Atlas Typesystem provides the high-level numbering system.  For example, area 1 has models 0100-0199, area 2 has models 0200-299, etc.   Each area's sub-models are dispersed along its range, ensuring there is space to insert additional models in the future.

In addition to the 7 metadata areas, the open metadata models introduces some base definitions and structures that used throughout the open metadata models.  These need to be loaded first and so we have added an Area 0 that includes these base definitions and the current models defined for Apache Atlas.  Thus the models numbers from 0000 to 0099 will look something like figure 1.

Details of the new models are shown below.  The original Apache models are linked to on page: Atlas Model.

Common Types

Common types describes the simple structures that are used repeatedly in open metadata.

Versioning

Versioned objects may follow a simple pattern where they can just be updated, or they can use a simple workflow where a draft can be prepared, reviews and approved.  Versions are linked together.  The previous version may simply be a Referenceable if it is created before versioning is activated.   The types for versioned metadata is shown in figure 3.

Authoritative Assets

Assets often describe objects in the real world.  They may have multiple names depending on the types of technology used to access them. As such an asset may have multiple identifiers.  The Authoritative Asset supports the de-duplication and consolidation of asset descriptions.  This is shown in figure 4.