Data Dictionary consists of database metadata. It has records about objects in the database.
Data Dictionary consists of the following information −
An example of Data Dictionary can be personal details of a student −
The following is the data dictionary for the above fields −
Here are the two types of data dictionary −
Active Data Dictionary
The DBMS software manages the active data dictionary automatically. The modification is an automatic task and most RDBMS has active data dictionary. It is also known as integrated data dictionary.
Passive Data Dictionary
Managed by the users and is modified manually when the database structure change. Also known as non-integrated data dictionary.