Information Models

Information models define meta data types that are stored in a repository database and used by tools and applications. Information models used with Microsoft® SQL Server™ 2000 Meta Data Services must be described using Unified Modeling Language (UML).

Meta Data Services distributes a set of standard information models called the Open Information Model (OIM). SQL Server 2000 preinstalls into the msdb database the standard OIM subject areas that describe Data Transformation Services (DTS) packages, data warehousing definitions, and online analytical processing (OLAP) cubes. These information models require no modification to perform the functions for which they are intended.

You can use these same standard models as a framework for building new applications. You can also create new models to work with using the Meta Data Services Software Development Kit (SDK). As long as your information models are defined in UML, you can use them in Meta Data Services.

Although you can create information models programmatically, most information models are created in modeling tools like Rational Rose. Custom information models must conform to the repository API. The repository API includes abstract classes that formally describe the elements you can include in a model. If you are creating a custom model, you may want to review the repository API for more information about the type information objects that the repository engine supports.

After you define and test an information model, you can install it in a repository database. Model installation creates the storage structure for your meta data. Tools and applications that use the model can populate the storage with instance data about the model definitions.

At run time, the repository engine reads the meta data and instantiates Component Object Model (COM) objects in a tool or application that correspond to the objects, relationships, and members of your information model. The COM interfaces that you use are derived from an information model installed in a repository database. In this way, the information model is a blueprint for the COM objects that the repository engine exposes.

You can also use Extensible Markup Language (XML) to import and export meta data between platforms, tools, and applications. For more information, see Using XML Encoding.

See Also

Creating and Extending Type Information

Designing Meta Data Types Using Information Models

Information Model Fundamentals

Meta Data Services SDK

OIM in Meta Data Services