Prior to FixPak 4, DB2 only checked for archive completion when a new log file was needed. Now DB2 checks for archive completion whenever the first active log changes. As a result, information is recorded to disk earlier and more often.
The benefit of this change is that if the system crashes, the information stored on disk (related to which log files are successfully archived) is more accurate and DB2 does not have to reissue the archive request for log files that are already archived.
There is no change to what DB2 does after detecting the successful archive of a particular log file.
DB2 now detects the completion of log archives earlier and will rename them earlier. Inactive truncated log files are deleted. As a result, the number of log files remaining in the active log path can be less than the LOGPRIMARY database configuration value. In this case, DB2 will create new log files when needed.
Before this change, restarting the database reduced the number of logs to equal the value of LOGPRIMARY. Now, when you restart a database, DB2 first examines the database log directory. If the number of empty logs is fewer than the number of primary logs, DB2 will allocate new logs to make up the difference. If more empty logs are available than there are primary logs in the database directory, DB2 will allow the database to be restarted with all the available empty logs in the database directory.
After database shutdown, any secondary log files in existence will remain in the active log path at restart time. To clear out the active log path, the DB2 ARCHIVE LOG command may be used.