Progress
Database Design
Guide
The Progress Database and the Relational Model
The Progress database is a relational database management system (RDBMS).You can add, change, manipulate, or delete the data and data structures in your database as your requirements change.
Database Schema and Metaschema
The physical structure of the Progress database consists of the elements of a relational database that you just read about: tables, columns, and indexes. The description of the database’s structure—the files it contains, the columns within the files, views, etc.—is called the database schema or the data definitions.
The underlying structure of a database that makes it possible to store and retrieve data is called the metaschema. That is, the metaschema defines that there can be database files and columns and the structural characteristics of those database parts. All metaschema table names begin with an underscore ( _ ). The metaschema is called the metaschema because it is data about the data.
NOTE: The metaschema is a set of tables that includes itself. Therefore, you can do ordinary queries on the metaschema to examine all table and index definitions, including the definitions of the metaschema itself.The sports Database
The sports database is one of several sample databases provided with the product; it is frequently used in the documentation to illustrate database concepts and programming techniques. Table 1–1 describes the contents of the sports database.
This database holds the information necessary to track customers, take and process orders, bill customers, and track inventory.
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