Protection_mode is unprotected at standby Database Analysis

Database Version

SQL> select * from V $ version;

 

Banner

Slave --------------------------------------------------------------------------------------------------------------------------------

Oracle Database 10g Enterprise Edition Release 10.2.0.1.0-64bi

PL/SQL release 10.2.0.1.0-Production

Core 10.2.0.1.0 Production

TNS for Linux: Version 10.2.0.1.0-Production

Nlsrtl version 10.2.0.1.0-Production

 

1. Problem description (Data guard adopts the maximum performance mode, but the protection_mode of the standby database is unprotected ?)

Master Database

SQL> select database_role, open_mode, protection_mode from V $ database;

 

Database_role open_mode protection_mode

--------------------------------------------------------------------------------------------

Primary read writeMaximum performance

 

Slave Database

SQL> select database_role, open_mode, protection_mode from V $ database;

 

Database_role open_mode protection_mode

--------------------------------------------------------------------------------------------

Physical standby mountedUnprotected

 

2. Problem Description

The slave database logs are normally used. The master database performs DML operations. You can also see the DML results when the slave database read is only enabled. It indicates that this data guard is correct. But why does the protection_mode of the standby database appear?UnprotectedWhat about it? With the help of a friend, I found the following description about the problem:

 

Maximize_standby_db_clause

Use this clause to specify the level of protection for the data in your database environment. You specify this clause from the primary database, which must be mounted but not open.

Note:

The protected and unprotected keywords have
Been replaced for clarity but are still supported. Protected is equivalent to maximize protection. Unprotected is
Equivalent to maximize performance.

Official link: http://docs.oracle.com/cd/B19306_01/server.102/b14200/statements_1004.htm#SQLRF00802

 

3. Problem Analysis

According to the explanation of the official document:

Protected = to maximize protection

Unprotected = to maximize performance

This makes it easy to see that in data guard, protection_mode = unprotected does not have any problems at all, except that it is called unprotected as another way of maximize performance.

 

4. Conclusion:

Protected = to maximize protection

Unprotected = to maximize performance

Some key parameter understanding problems. The best solution is to find the Oracle official file.

 

Finally, you can go to bed with peace of mind. To solve one problem every day is to make progress.

Link: http://space.itpub.net/26442936/viewspace-750323