Question

Difference between data dictionary and system catalog

Answer 1

Collection of these metadata is stored in the data dictionary or system catalog. Usually, system catalogs are accessed by the DBMS to perform various transactions and data dictionary has the user accessible views that are accessed by the developers/ designers/ users. It is a database about the database objects.

Answer 2

Data dictionary (tables) vs System catalog (catalog)

Data dictionary:

• It is also called metadata repository.
• It mainly contains the data about objects, their relationships with other objects and main data of a user.

System catalog:

• Allows you to search for items in a specific libraries. Example: movies, books.
• It contains very important details about the database in form of detailed tables.
• It basically specifies the framework of the database.
• Details cannot be modified by the user.