Features of Oracle DATA GUARD

We all know that the main function of Oracle data guard is disaster tolerance. We all know that data guard has the following features: high availability, performance improvement, DATA protection, and fault recovery.

Oracle data guard can be divided into two types: Physical STANDBY and logical STANDBY. The biggest difference between the two is that physical STANDBY applies archive logs of the master database, while logical STANDBY applies SQL statements extracted from the archive logs of the master database.

The difference between the two determines that physical STANDBY is consistent with the master database regardless of the logical structure and physical structure, while logical STANDBY only needs to ensure that the logical structure is consistent, when SQL statements are applied to logical STANDBY, the database can be opened.

From the protection mode of Oracle data guard, there are three different protection modes:

Maximize protection: This mode ensures synchronization between the master database and the slave database. Under any circumstances, damage to the master database will not cause the loss of submitted data. If there is a network problem between the master database and the slave database, or the slave database itself has a problem, the master database stops processing data.

Maximum availability: This mode is similar to the above mode, which ensures synchronization between the master database and the slave database. The difference is that when the network or slave database is unavailable, the master database can continue to process.

Maximum performance: the master and slave databases are asynchronous. In this mode, part of the data may be lost when the master database is damaged. However, this mode has the best performance because it has the least load on the master database.

The above content is an introduction to Oracle data guard. I hope you will find some gains.