Databases Reference
In-Depth Information
Table 14-1.
Determining the Action to Take
Type of Failure
Status Column of V$LOG
Action
Recipe
One member failed in
multiplexed group
N/A
Drop/re-create member.
Recipe 14-2
All members of group
INACTIVE
Clear logfile or drop/re-create log group.
Recipe 14-3
All members of group
ACTIVE
Attempt checkpoint, and if successful,
clear logfile. If checkpoint is unsuccessful,
perform incomplete recovery.
Recipe 14-4
All members of group
CURRENT
Attempt to clear log, and if unsuccessful,
perform incomplete recovery.
Recipe 14-5
Inspect your target database alert.log file to determine which online redo log file member is unavailable. Oracle error
messages related to online redo log file failures are ORA-00312 and ORA-00313. Here's an example of errors written to
the alert.log file when there are problems with an online redo log file:
ORA-00313: open failed for members of log group 2 of thread 1
ORA-00312: online log 2 thread 1: '/u02/oraredo/o12c/redo02b.rdo'
Query V$LOG and V$LOGFILE views to determine the status of your log group and the member files in each group:
SELECT
a.group#
,a.thread#
,a.status grp_status
,b.member member
,b.status mem_status
,a.bytes/1024/1024 mbytes
FROM v$log a,
v$logfile b
WHERE a.group# = b.group#
ORDER BY a.group#, b.member;
Here is some sample output:
GROUP# THREAD# GRP_STATUS MEMBER MEM_STA MBYTES
------ -------- ---------- ------------------------------ ------- --------
1 1 INACTIVE /u01/oraredo/o12c/redo01a.rdo 50
1 1 INACTIVE /u02/oraredo/o12c/redo01b.rdo 50
2 1 CURRENT /u01/oraredo/o12c/redo02a.rdo 50
2 1 CURRENT /u02/oraredo/o12c/redo02b.rdo 50
3 1 INACTIVE /u01/oraredo/o12c/redo03a.rdo 50
3 1 INACTIVE /u02/oraredo/o12c/redo03b.rdo 50
If only one member of a multiplexed group has experienced a failure, then proceed to Recipe 14-2. If all members
of a redo log group have experienced a failure and your database is open, it will hang (cease to allow transactions to
process) as soon as the archiver background process cannot successfully copy the failed online redo log file members.
