Switching a Log File

Switching a Log File
When a log switch occurs, the log writer (LGWR) process stops writing to the current
online redo log group and starts writing to the next available redo log group. After a
log switch, the current online redo log group becomes inactive, and the next available
online redo log group becomes the current online redo log group.
You can force a log switch to make the current redo group inactive and available for
redo log maintenance operations. Forcing a log switch is useful in configurations with
large redo log files that take a long time to fill. For example, you might want to:
■ Drop the current redo group, but are not able to do so until the group is inactive
■ Archive the current online redo log group members immediately, even though
they are not yet completely filled
... zobacz całą notatkę