AIM Components - Teradata Meta Data Services

AIM Components

An AIM consists of the following components:

Class descriptions define a type of meta data in the repository.

A class description is similar to a class in the C++ programming language.

In the sample metamodel shown in Figure 1, AutoCorporation and AutoDivision are examples of class descriptions.

An instance of a class description in the repository is called a class object or object. Big Guy Motors is an AutoCorporation object and American Autos is an AutoDivision object.

Property descriptions are the data fields associated with class descriptions.

The Auto class description might contain properties such as weight, base price, fuel tank, and other options.

Relationship descriptions create an association between two class descriptions.

In Figure 2, relationship descriptions are defined as “DivisionMakesAutos” and “DivisionMakesSUVs”. These relationship descriptions enable linking AutoDivision objects with specific Auto and SUV objects.

In Figure 2, these relationship descriptions are used to associate the AutoDivision object American Autos with the Auto objects Tortoise and Yearling and to the SUV objects Hawk and Vulture.

Relationship descriptions have the following characteristics:

Each relationship description relates two class descriptions.

An instance of a relationship description in the MDS repository creates a persistent association between two objects and is called a relationship.

A collection is a set of objects that have relationships to the same object (called the source object).

In a relationship description, one class description is defined as the origin and the other the destination.

Figure 2 shows examples of relationships and collections.

Figure 2: Relationship/Collection Example

AIMs are extensible. Class descriptions and relationship descriptions can be added or deleted from existing AIMs and property descriptions can be added or deleted from existing class descriptions.