Action if the next log file contains the last checkpoint

The database server does not suspend processing when the next log file contains the last checkpoint or the oldest update. The database server always forces a checkpoint when it switches to the last available log, if the previous checkpoint record or oldest update that is not yet flushed to disk is located in the log that follows the last available log. For example, if four logical-log files have the status shown in the following list, the database server forces a checkpoint when it switches to logical-log file 3.
Log file number
Logical-log file status
1
U-B----
2
U---C--
3
F
4
U-B---L