Hour 21. Working with the System Catalog

During this hour, you learn about the system catalog, commonly referred to as the data dictionary in some relational database implementations. By the end of this hour, you will understand the purpose and contents of the system catalog and will be able to query the system catalog to find information about the database based on commands that you have learned in previous hours. Each major implementation has some form of a system catalog that stores information about the database itself. This hour shows examples of the elements contained in a few different system catalogs.

The highlights of this hour include

• What the system catalog is

• How the system catalog is created

• What data is contained in the system catalog

• Examples of system catalog tables

• Querying the system catalog

• Updating the system catalog