6.7 DBA_HIST_LOG

DBA_HIST_LOG displays historical log file information from the control file. This view contains snapshots of V$LOG.

Column Datatype NULL Description

SNAP_ID

NUMBER

NOT NULL

Unique snapshot ID

DBID

NUMBER

NOT NULL

Database ID for the snapshot

INSTANCE_NUMBER

NUMBER

NOT NULL

Instance number for the snapshot

GROUP#

NUMBER

NOT NULL

Log group number

THREAD#

NUMBER

NOT NULL

Log thread number

SEQUENCE#

NUMBER

NOT NULL

Log sequence number

BYTES

NUMBER

Size of the log (in bytes)

MEMBERS

NUMBER

Number of members in the log group

ARCHIVED

VARCHAR2(3)

Archive status (YES) or NO)

STATUS

VARCHAR2(16)

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 may or may not be archived.

  • INVALIDATED - Archived the current redo log without a log switch.

FIRST_CHANGE#

NUMBER

Lowest system change number (SCN) in the log

FIRST_TIME

DATE

Time of the first SCN in the log

CON_DBID

NUMBER

The database ID of the PDB for the sampled session

CON_ID

NUMBER

The ID of the container that CON_DBID identifies. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data

See Also:

"V$LOG"