Downloading archived redo logs from Amazon S3

You can download archived redo logs on your DB instance using the rdsadmin.rdsadmin_archive_log_download package. If archived redo logs are no longer on your DB instance, you might want to download them again from Amazon S3. Then you can mine the logs or use them to recover or replicate your database.

Note

You can't download archived redo logs on read replica instances.

Downloading archived redo logs: basic steps

The availability of your archived redo logs depends on the following retention policies:

• Backup retention policy – Logs inside of this policy are available in Amazon S3. Logs outside of this policy are removed.

• Archived log retention policy – Logs inside of this policy are available on your DB instance. Logs outside of this policy are removed.

If logs aren't on your instance but are protected by your backup retention period, use rdsadmin.rdsadmin_archive_log_download to download them again. RDS for Oracle saves the logs to the /rdsdbdata/log/arch directory on your DB instance.

To download archived redo logs from Amazon S3

1. Configure your retention period to ensure your downloaded archived redo logs are retained for the duration you need them. Make sure to COMMIT your change.

   RDS retains your downloaded logs according to the archived log retention policy, starting from the time the logs were downloaded. To learn how to set the retention policy, see Retaining archived redo logs.

2. Wait up to 5 minutes for the archived log retention policy change to take effect.

3. Download the archived redo logs from Amazon S3 using rdsadmin.rdsadmin_archive_log_download.

   For more information, see Downloading a single archived redo log and Downloading a series of archived redo logs.

   Note

   RDS automatically checks the available storage before downloading. If the requested logs consume a high percentage of space, you receive an alert.

4. Confirm that the logs were downloaded from Amazon S3 successfully.

   You can view the status of your download task in a bdump file. The bdump files have the path name /rdsdbdata/log/trace/dbtask-task-id.log. In the preceding download step, you run a SELECT statement that returns the task ID in a VARCHAR2 data type. For more information, see similar examples in Monitoring the status of a file transfer.

Downloading a single archived redo log

To download a single archived redo log to the /rdsdbdata/log/arch directory, use rdsadmin.rdsadmin_archive_log_download.download_log_with_seqnum. This procedure has the following parameter.

Parameter name	Data type	Default	Required	Description
seqnum	number	—	Yes	The sequence number of the archived redo log.

The following example downloads the log with sequence number 20.

SELECT rdsadmin.rdsadmin_archive_log_download.download_log_with_seqnum(seqnum => 20) 
       AS TASK_ID 
FROM   DUAL; 

Downloading a series of archived redo logs

To download a series of archived redo logs to the /rdsdbdata/log/arch directory, use download_logs_in_seqnum_range. Your download is limited to 300 logs per request. The download_logs_in_seqnum_range procedure has the following parameters.

Parameter name	Data type	Default	Required	Description
start_seq	number	—	Yes	The starting sequence number for the series.
end_seq	number	—	Yes	The ending sequence number for the series.

The following example downloads the logs from sequence 50 to 100.

SELECT rdsadmin.rdsadmin_archive_log_download.download_logs_in_seqnum_range(start_seq => 50, end_seq => 100) 
       AS TASK_ID 
FROM   DUAL;