Standby log gap issue solved

We had a physical standby database that is behind the primary database for several days. We found that there were gaps. So we restored the archived logs from tape by RMAN to their original destination. Oracle is smart enough to automatically fetch those archived logs to the destination. And we don't need to register them at all on the standby ( our environment is 10g).

However, we found the MRP0 process status is always WAIT_FOR_LOG when issue the following sql:

SELECT PROCESS, STATUS,SEQUENCE#,BLOCK#,BLOCKS, DELAY_MINS FROM
V$MANAGED_STANDBY

Later I found out that in the alert log, there is a line showing:

Media Recovery Delayed for 479 minute(s) (thread 1 sequence 52361)

I reallized we have used the DELAY=480 attribute of the LOG_ARCHIVE_DEST_2 initialization parameter on the primary database to delay applying archived redo log files to the standby database.

So I tryied the following command which I found in the documentaton on the standby:

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE NODELAY;

Oracle started the redo apply immediately. By this way we are able to catch up and solve this log missing and apply lag issue.