The Importance of the Relational System Catalog

The heart of any relational database management system is the system catalog that documents the database objects and system settings being used. The system catalog offers a wealth of information about your DBMS. You can think of it as the knowledge base of every piece of data known to the system. For this reason, it is important that DBAs understand what is in the system catalog, as well as how to access and manipulate the information it contains.Of course, depending upon the DBMS you use, the system catalog may go by another name. Consult Table 1 below for a summary of the name used by the most popular relational systems.Table 1: A Catalog by Any Other Name . . .A relational DBMS requires a system catalog, but it may be called something different depending upon the particular DBMS you are using:In Oracle it is referred to as the Data Dictionary.In SQL Server it is referred to as the System Catalog.In DB2 it is referred to as either the DB2 Catalog or System Catalog.In MySQL it is refe...