Database log files grow constantly. The ability to truncate a database log file, and optionally archive the file before truncation while the database is online, provides DBAs with the ability to save log file information, and also manage file growth.
As you configure your database to truncate and possibly archive your log file, consider the following:
There is only one active log file, and it is named dbname.lg.
When the log file is truncated, licensing information and the startup parameters of the primary broker are re-written to the log file.
If truncation is configured to occur at a specific time, and the database is offline or in single-user mode, the log file is not truncated.
If truncation is configured to occur when the log file reaches a specific size, and the database is offline or in single-user mode when the size is reached, the log file is not truncated. If the truncation size parameters are met the next time the database is brought online in multi-user mode, the log file is truncated then.
If the database is in the middle of writing a message when the truncation size or time is reached, the log file is truncated after the message writing completes.
You can configure your log file to be truncated by both time and size, and both are honored.
If you choose to archive your log file, in the time between starting your database and archiving the log file, an interim log file is created and maintained in the archive directory or the database directory if no archive directory is specified.
You can manage the criteria for truncating and archiving your log file through startup parameters, the _DbParams VST, or with PROMON.
There is only one active log file, and it is named dbname.lg.
