V$STANDBY_LOG displays information about standby redo logs. Standby redo logs are similar to online redo logs, but standby redo logs are only used on a standby database that is receiving redo data from the primary database.
Log group number
Database ID of the primary database to which the standby redo logfile is assigned. If the standby redo logfile is unassigned, the value UNASSIGNED will be displayed.
Log thread number
Log sequence number
Size of the log (in bytes)
Number of bytes used in the log
Archive status (YES) or (NO)
UNASSIGNED - 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.
ACTIVE - Log is active but is not the current log. It is needed for failure recovery. It may be in use for block recovery. It may or may not be archived.
Lowest SCN in the log
Time of first SCN in the log
Last change number made to this datafile. Set to NULL if the datafile is being changed.