What Is a MDF File?

by JC Torpey
An MDF file can serve several functions.

An MDF file can serve several functions.

Image by Flickr.com, courtesy of Mike Dong

The MDF file extension is one of many obscure file types. Different computer and software related tasks require different kinds of file types or extensions. The MDF file type is one of the more uncommon file types related to image files and it also has uses within the Microsoft SQL Server database.

History

The MDF file format, known at one time as Max Disk Formatting, is an obsolete program. Floppy disks needed this program to format them and also for turning smaller file formats into larger formats, or non-standard formats. Many programs do not understand this particular MDF file format because of its non-use in modern computing. The only use it has in modern times is the ability to format data that a DOS program cannot, which is rare.

Types

MDF files can be images or database files. The image files are Media Descriptor Files and are similar to an ISO or BIN file type, as they are raw images of a disk, but have different properties. They are a proprietary image format owned by Alcohol 120% and sometimes used by Daemon Tools and other disk emulation programs. The database files are Master Database Files used only with Microsoft’s SQL Sever database program and are a primary data file format for SQL Express.

Function/Images

An MDF image file format’s functionality is to burn a copy of a raw image of a CD or DVD disk. A raw image is an exact copy of all information contained on the disk, including data, photos, music, writing or album or sleeve covers. This format also backs up information on hard drives as raw images as well. It needs a special program to open and mount the file, such as Alcohol 120%, Daemon Tools, ISO Buster or Magic ISO.

Function/Database

The MDF file format’s database functionality is only available within the SQL Server Express Edition, which is a lightweight version of the full SQL Server version. The full database of the SQL Server Express Edition is stored in the MDF file and at one point was supposed to replace the MSDE, or Microsoft SQL Data Engine. MDF is the recommended file type, although any type is possible in any SQL Server Edition.

Considerations

Because the MDF file type is obscure, it is always better to use a more recognized and easy-to-work with file type or extension. An ISO or BIN format is similar and easier to work with for imaging purposes. For Microsoft’s SQL Server software, the MDF file type is located in both the master and primary log files and any file type or extensions are possible, but the MDF file type is easier to tell what kind of information is included within the file.

About the Author

JC Torpey (Jessica Zuzierla), lives in Philadelphia and has authored works since 1997. She is published on various sites including Associated Content, Youserbase.org and other websites and their respective blogs. Torpey attends The Art Institute of Pittsburgh for an associate's degree in interactive media and Web design.

Photo Credits

  • Image by Flickr.com, courtesy of Mike Dong