mdf is a preferred extension of the primary database file. It is not a type of file. You can use another extension (*. gbn) to create a primary database file without any error. The primary data file contains columns, fields, rows, indexes, tables, and data added by an application.

What are MDF files in SQL Server?

mdf extension is a Master Database File used by Microsoft SQL Server to store user data. It is of prime importance as all the data is stored in this file. The MDF file stores users data in relational databases in the form columns, rows, fields, indexes, views, and tables.

How do I open an MDF file?

Right-click your MDF file and select “Open with.” Select Daemon tools from the options and the image will mount as a DVD. Windows Explorer will pick it up and you will be able to run or explore the disk just as you would if it were a real DVD.