What are the techniques for storing versions?

• The set of differences between two versions is called a delta.

• Full files

--Complete files
--Large storage space

• Forward Delta files

--Never need to modify existing library file data
--All updates made by appending additional new data, in place, to the end of the file
--Ensures that all versions of a file are available, but uses a minimum of disk space

• Reverse Delta files

--Saves only the latest version of a file as a full version
--Other versions are saved as version deltas, reflecting only the differences between versions
--Ensures that all versions of a file are available, but uses a minimum of disk space