REDO LOG MEMBER STATUS 和 REDO LOG GROUP STATUS

V$LOG 中列出的是REDO LOG GROUP STATUS

Log status:

·         UNUSED - Online redo log has never been written to. This is the state of a redo log that was just added, or just after a RESETLOGS , when it is not the current redo log.

·         CURRENT - Current redo log. This implies that the redo log is active. The redo log could be open or closed.

·         ACTIVE - Log is active but is not the current log. It is needed for crash recovery. It may be in use for block recovery. It may or may not be archived.

·         CLEARING - Log is being re-created as an empty log after an ALTER DATABASE CLEAR LOGFILE statement. After the log is cleared, the status changes to UNUSED .

·         CLEARING_CURRENT - Current log is being cleared of a closed thread. The log can stay in this status if there is some failure in the switch such as an I/O error writing the new log header.

·         INACTIVE - Log is no longer needed for instance recovery. It may be in use for media recovery. It might or might not be archived.

 

V$LOGFILE 中列出的是REDO LOG MEMBER STATUS

Status of the log member:

·         INVALID - File is inaccessible

·         STALE - File's contents are incomplete

·         DELETED - File is no longer used

·         null - File is in use