The protection level of DataGuard10g is RESYNCHRONIZATION.

Check the value of protection_mode and protection_level of v $ database after Oracle's dataguard is created. For example, the value of protection_mode is MAXIMUMAVAILA.

After the data guard of Oracle is created, check the value of protection_mode and protection_level of v $ database. For example, the value of protection_mode is maximum availa.

After the data guard of Oracle is created, check the value of protection_mode and protection_level of v $ database. If the value of protection_mode is maximum availability, the value of protection_level should also be this value. If it is not the value, it is RESYNCHRONIZATION. This indicates that the log synchronization of data guard is abnormal.

You can also see this information in the alert. log of the standby database: "Primary database is in maximum performance mode ". It indicates that the master database is actually the maximum performance mode, rather than the pre-configured maximum available mode.

Oracle data guard automatically degrades to the maximum performance mode when the master database is set to the maximum available mode. This result makes log synchronization no longer real-time.

Check the data dictionary view v $ database

SQL> r
1 * select protection_mode, protection_level from v $ database

PROTECTION_MODE PROTECTION_LEVEL
----------------------------------------
MAXIMUM AVAILABILITY RESYNCHRONIZATION

Check the database initialization parameter log_archive_dest *

SQL> show parameter log_archive_dest

NAME TYPE VALUE
-----------------------------------------------------------------------------
Log_archive_dest_1 string LOCATION = + VG2/
Log_archive_dest_2 string service = oxdb_standby lgwr asyn
C affrem valid_for = (online_lo
Gfiles, primary_role) db_unique
_ Name = oxdg

Analysis

Oracle data guard has three Protection modes: maximum protection mode, maximum available mode, and maximum performance mode.

Minimum Requirements for Maximum Protection Mode
Redo Archival Process LGWR
Network Transmission Mode SYNC
Disk Write Option affrem
Standby Redo Logs? Yes
Standby Database Type Physical Only

Minimum Requirements for Maximum Availability Mode
Redo Archival Process LGWR
Network Transmission Mode SYNC
Disk Write Option affrem
Standby Redo Logs? Required for physical standby databases only. Standby redo logs are not supported for logical standby databases.
Standby Database Type Physical or Logical

Minimum Requirements for Maximum Performance Mode
Redo Archival Process LGWR or ARCH
Network Transmission Mode ASYNC when using LGWR process. Not applicable when using the ARCH process.
Disk Write Option noaffrem
Standby Redo Logs? Required for physical standby databases using the LGWR process.
Standby Database Type Physical or Logical