An encyclopedia is the repository of information that you store about your enterprise architecture. Physically, an encyclopedia is a database on an SQL Server.

The encyclopedia includes all components of your enterprise architecture, namely, the diagrams and definitions that make up your architecture, and references to any external documents or internal documents (documents that you have imported into the Files table of the encyclopedia for local storage).

Structurally, an encyclopedia is a collection of system tables, user tables and external files, which all combined form a single repository. System tables contain information about the database itself, such as the date of last backup. User tables contain the encyclopedia objects that you work with, such as diagrams, definitions and relationships. The User tables also maintains records for external files - you can export these files (for example, text, bitmap, metafiles), edit them with other applications, and import them back into the repository. With System Architect encyclopedias, you can take advantage of features that make relational databases useful, especially when you are designing or running reports.

System Architect supports SQL Server 2005 and SQL Server 2005 Express servers as the underlying encyclopedia repositories. The repository in use makes no difference to the System Architect functions or to the method used to access encyclopedias. However, the user authentication options you can use to access encyclopedias vary according to the server types as follows: