Abstract: A computer system synchronizes data in multiple remote database files with data in a master database file. The system creates the remote files by copying data from the master file. For each remote file created, the system also creates a backup file. The backup file reflects contents of the remote file when the remote file was created or last synchronized, i.e., before a user can modify data in the remote file. From time to time, the system synchronizes data in the master file and a remote file. The system compares corresponding data in the master, remote, and backup files to determine which file (remote or master) has a more current version of the data. The system then updates the file that has the less current data with data from the file that has the more current data. After synchronizing the files, the system copies all data from the remote file to the backup file (or alternately creates a new backup file).