Guide to Oracle Data Guard Protection Modes
1. Maximum Protection Mode
1) This mode provides the highest level of data protection;
2) Requires at least one physical standby database to receive the redo log before the primary database transaction can commit;
3) If the primary database cannot find a suitable standby database to write to, the primary database will automatically shut down to prevent unprotected data from occurring;
4) Advantages: This mode guarantees zero data loss on the standby database;
5) Disadvantages: The automatic shutdown of the primary database affects its availability, and transactions require standby recovery before they can commit. It places very high demands on the network and other objective conditions, and the primary database performance suffers a significant impact as a result.
2. Maximum Availability Mode
1) This mode provides data protection capability second only to “Maximum Protection Mode”;
2) Requires at least one physical standby database to receive the redo log before the primary database transaction can commit;
3) If the primary database cannot find a suitable standby database to write to, it will not shut down but will temporarily downgrade to “Maximum Performance Mode” until the issue is resolved;
4) Advantages: In the absence of problems, this mode guarantees zero data loss on the standby database, serving as a compromise approach;
5) Disadvantages: During normal operation, the primary database performance is affected by many factors.
3. Maximum Performance Mode
1) This mode is the default and ensures the highest availability of the primary database;
2) Guarantees that primary