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
-
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.
-
Wait up to 5 minutes for the archived log retention policy change to take effect.
-
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.
-
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-
. In the preceding download step, you run atask-id
.logSELECT
statement that returns the task ID in aVARCHAR2
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 |
---|---|---|---|---|
|
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 |
---|---|---|---|---|
|
number |
— |
Yes |
The starting sequence number for the series. |
|
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;