Post date: 03-Mar-2011 15:39:05
Nologging Operations on the Primary or Standby Site
SELECT NAME, UNRECOVERABLE_CHANGE#,
TO_CHAR (UNRECOVERABLE_TIME,'DD-MON-YYYY HH:MI:SS')
FROM V$DATAFILE;
Determining Which Log Files Were Not Received by the Standby Site
SELECT LOCAL.THREAD#, LOCAL.SEQUENCE# FROM
(SELECT THREAD#, SEQUENCE# FROM V$ARCHIVED_LOG WHERE DEST_ID=1) LOCAL
WHERE LOCAL.SEQUENCE# NOT IN
(SELECT SEQUENCE# FROM V$ARCHIVED_LOG WHERE DEST_ID=2 AND
THREAD# = LOCAL.THREAD#);
Determining Which Log Files Were Applied to the Standby Database
SELECT THREAD#, MAX(SEQUENCE#) AS "LAST_APPLIED_LOG"
FROM V$LOG_HISTORY
GROUP BY THREAD#;
Determining the Progress of Redo Apply
SELECT ARCHIVED_THREAD#, ARCHIVED_SEQ#, APPLIED_THREAD#, APPLIED_SEQ#
FROM V$ARCHIVE_DEST_STATUS;
Monitoring the Process Activities
SELECT PROCESS, CLIENT_PROCESS, SEQUENCE#, STATUS
FROM V$MANAGED_STANDBY;
Data Guard Managed Recovery Apply Process Running Slowly [ID 1448626.1]
The managed recovery process MRP0 is running successfully but is slow in applying logs. The trace files for the recovery slaves show the following type of messages:
*** 2012-03-20 08:29:27.211
Recovery is unrecoverable because 6 other slaves require space.
*** 2012-03-20 08:29:37.908
Recovery is unrecoverable because it fails to get a free buffer.
*** 2012-03-20 08:29:38.490
Recovery is unrecoverable because 6 other slaves require space.
*** 2012-03-20 08:29:59.932
Recovery is unrecoverable because it fails to get a free buffer.
Note the number of slaves affected can be different depending on the environment
Increase the buffer cache on the standby.
In addition, check and incorporate the following recommendations to your standby environment for improved recovery performance:
Increase the number of db_writer_processes to 4.
Make sure the primary online redo logs are adequately sized. In general the larger the log size the better recovery performance is due to decreased number of checkpoints.
If using block change tracking file on the standby set _bct_public_dba_buffer_size=536870912
Set db_block_checking=OFF on the standby