Repeat the worked exercise in Section 19.6.1, but this time look for shared data on your system. Is the data updated by one person and viewed by many, or have you got files or databases which are...

Repeat the worked exercise in Section 19.6.1, but this time look for shared data on your system. Is the data updated by one person and viewed by many, or have you got files or databases which are updated by several people? If the latter, find out what methods are used to prevent two users changing the same data at the same time. There may be no mechanism at all, a computerized one (for example, locking) or a social protocol (for example, a floppy disk is passed around).