Relationship between Rman backup reservation and Control_file_record_keep_time

Available version: Version 8.1.7.0 and later

In the reuse section of the control file, the backup metadata that has the Rman backup is preserved. How long to keep depends on control_file_record_keep_time. This parameter indicates the minimum number of days that can be retained for reusing information metadata in a data file.

Scenario: A record needs to be plugged into the reuse part of the control file, but the reuse section doesn't have enough space, so the oldest record will be deleted.

A backup retention policy is used to satisfy a rule that has enough backups when it comes to recovery or other needs. So if the value of the control_file_record_keep_time is smaller than the retention policy, then the metadata information for the backups will be overwritten before the Rman has discarded (obsolete) the backups. Therefore, Control_file_record_keep_time recommends setting a value that is greater than the retention policy.



Suggestions:

Control_file_record_keep_time = retention period + Level 0 backup interval + 1

Note:

Obsolete: is a backup that exceeds the retention policy time

Expired: is a nonexistent file.