The logging system tracks all changes made to each location's tables since the last time the XDB Server BACKUP command was used on the location (or since the last time logging was reset for the location). The logging system maintains a separate series of log files for each location.
In the event of a serious system failure, such as a disk crash or other media failure, you can restore a backup copy of the location's tables and then issue the ROLLFORWARD command to apply the contents of the location's current log files to the restored location tables. These actions bring your tables up to date (to the time just prior to the system failure).
By default, the Forward Log path (where location log files are stored) is the same as your location path. You can and should change the name and path for your location log file storage. Ideally, log files should be placed on a different physical device than the location tables they are logging. This precaution protects against an independent media failure such as a hard disk crash.
You can change the current log path for a location by using the SET LOG command. See the SQL Reference for more information on the SET LOG command.
Location logging should be reset after using the BACKUP command to archive a location and its log files. If you use a different method to create your backups (such as an operating system BACKUP command), you can reset the location log files by deleting the current log files from your operating system prompt.
The logging system automatically creates a new series of location log files when you commence entering transactions. See the chapter Backup and Recovery for more information.