Macintosh: Meaning of the Desktop DB & Desktop DF Files

Why do I have these files on my Macintosh?:

╩Desktop DB
* Desktop DF
This article has been archived and is no longer updated by Apple.
The Desktop DB/Desktop DF files are invisible files that are not normally seen by users. The files were original created by the Desktop Manager of AppleShare 2.0 running under System 6.0.x to maintain information in addition to the Finder's Desktop file at that time. There were designed to be more high performance databases to support faster access to information for AppleShare servers.

Under System 7, functions of the Desktop Manager were incorporated into the Finder along with File Sharing support. The limits of the resource manager were being overextended by the old style resource-based Desktop file. The Finder database file was redesigned as a file storing information in the data fork in a faster and more efficient form.

The primary information stored in the Finder's Desktop DB/Desktop DF files is the mapping of icon display information for application and their associated files. This includes application signatures (creators) and associated file types. This information is used by the Finder to determine what application to launch when a file is double-clicked and to ascertain whether a file can be opened by a drag'n'drop action onto an application.

Other files with their own icon information also have their icon mappings stored in this database. Several flags associated with every file, such as whether the file is an alias or stationery file, whether the file name is locked from change, and whether the file is visible or not are maintained in the database. Other information stored in these files includes Comments from Finder Get Info windows, position information of icons within Finder container windows, and the positioning of the Finder windows.

These are the files that are rebuilt by holding down the Command and Option keys during Finder startup.

More details about the Finder database can be found in Inside Macintosh:Macintosh Toolbox Essentials, chapter 7, Using the Finder Interface.
Published Date: Feb 18, 2012