DDUPD upgrades the Visual SourceSafe database to a new format. The new format will initialize the database to take advantage of the Label Promotion and the Performance Enhancements introduced in VSS 6.0. During installation the database may have been upgraded. If a ..\data\labels folder exists, the database is in the new format. The database can be 'downgraded' with this utility also.
Notes about upgrading:
Back up your VSS database before upgrading!
Make sure all users exit VSS before upgrading to the new version. They can, however, have files checked out during the upgrade.
By default, when you upgrade to VSS 6.0 the database format is the same as that of VSS 5.0 (and 4.0a). If you have Macintosh, UNIX, NT 3.51, or 16-bit clients, you must stay with the older database format. (You also must stay with the 5.0 database format until you own VSS 6.0 licenses for everyone.)
If you don't have issues with backward compatibility, you can upgrade the database to the new format, which will allow you to take advantage of some performance enhancements in VSS 6.0. With the new database format, any command that asks VSS to copy a file to your local drive (such as Get, Check Out, Undo Check Out, Deploy, etc.), will be faster. The greatest performance enhancement is seen in situations where the file already exists and no copy is needed.