The database log (.lg) file expands as you use the database. If it becomes too large, you can use the PROLOG utility, in either an offline or online mode, to reduce the event log file's size. Using the PROLOG utility, you can:
Truncate log entries offline — Removes old log entries. To remove log entries from an .lg file, use the OpenEdge Log Maintenance (PROLOG) utility or a text editor. The syntax to use the PROLOG utility in the offline mode is described in Removeold log entries.
Truncate log file entries online — Removes entries in the database log file, and re-logs the database startup parameters while the database is online. The online activity is intended to help you avoid bringing the database down and restarting it after the database log file has been truncated. Using this approach, the need to shutdown the database to archive the log file is eliminated. However, keep in mind that it is possible to lose some messages while performing this procedure due to the nature of the real-time processing. The syntax to use the PROLOG utility in the online mode is described in Truncatethe database log file.
Caution: During the time in which the multi-stepped online truncation process occurs, some messages written to the log file might get lost because the database is neither quiet nor latched/locked to prevent writes.