Data Guard 提供三種資料保護模式：最大保護（Maximum Protection），最高可用（Maximum Availability）和 最高效能（Maximum Performance）。

[oracle@monkey01 ~]$ sqlplus / as sysdba
SQL> alter system set log_archive_dest_2='SERVICE=monkeysdb LGWR SYNC AFFIRM valid_for=(online_logfiles,primary_role) db_unique_name=monkeysdb' scope=spfile;
SQL> shutdown immediate;
SQL> startup mount;
SQL> alter database set standby database to maximize availability;
SQL> alter database open;
SQL> select DEST_ID , DATABASE_MODE , RECOVERY_MODE , PROTECTION_MODE from v$archive_dest_status where DEST_ID=2;
   DEST_ID DATABASE_MODE   RECOVERY_MODE           PROTECTION_MODE
---------- --------------- ----------------------- --------------------
         2 OPEN_READ-ONLY  MANAGED REAL TIME APPLY MAXIMUM AVAILABILITY
         
SQL> alter system set log_archive_dest_2='SERVICE=monkeysdb LGWR SYNC AFFIRM valid_for=(online_logfiles,primary_role) db_unique_name=monkeysdb' scope=spfile;
SQL> shutdown immediate;
SQL> startup mount;
SQL> alter database set standby database to maximize protection;
SQL> alter database open;
QL> select DEST_ID , DATABASE_MODE , RECOVERY_MODE , PROTECTION_MODE from v$archive_dest_status where DEST_ID=2;
   DEST_ID DATABASE_MODE   RECOVERY_MODE           PROTECTION_MODE
---------- --------------- ----------------------- --------------------
         2 OPEN_READ-ONLY  MANAGED REAL TIME APPLY MAXIMUM PROTECTION
         
SQL> alter system set log_archive_dest_2='SERVICE=monkeysdb LGWR ASYNC valid_for=(online_logfiles,primary_role) db_unique_name=monkeysdb' scope=spfile;
SQL> shutdown immediate;
SQL> startup mount;
SQL> alter database set standby database to maximize performance;
SQL> alter database open;
SQL> select DEST_ID , DATABASE_MODE , RECOVERY_MODE , PROTECTION_MODE from v$archive_dest_status where DEST_ID=2;
   DEST_ID DATABASE_MODE   RECOVERY_MODE           PROTECTION_MODE
---------- --------------- ----------------------- --------------------
         2 OPEN_READ-ONLY  MANAGED REAL TIME APPLY MAXIMUM PERFORMANCE