System Catalog

Definition - What does System Catalog mean?

A system catalog is a group of tables and views that incorporate vital details regarding a database. Every database comprised of a system catalog and the information in the system catalog specifies the framework of the database.

For instance, the data dictionary language (DDL) for every table in the database is saved in the system catalog.

Techopedia explains System Catalog

The system catalog is a vital part of a database. Inside the database, there are objects, which include tables, views and indexes. Basically, the system catalog is a set of objects, which includes information that defines:

Other objects included in the database
The database structure itself
Several other vital pieces of information

The system catalog intended for implementation can be split into logical groups of objects. This is to offer tables that are accessible by not just the admin of the database, but also by all other database users as well. For instance, users might want to see the specific database privileges that they have been granted with; however, have no requirement to find out regarding the database's processes or internal structure.

A user generally looks up the system catalog to gain information regarding the user's own objects as well as privileges, while the database admin must be capable of inquiring about any event or structure inside the database. In certain implementations, one can find system catalog objects, which can be accessible only by the administrator of the database.

A system catalog is extremely important to database admins or all other database users who wish to understand the nature and structure of a database. The system catalog lets order to be kept, not just by the users and database administrator, but also by the database server as well.