[Oracle] Data Guard-Redo Application

[Oracle] Data Guard-Redo applications physical Standby and logical Standby Log application services are divided into two types, one is physical Standby Redo applications, similar to media recovery, its advantage is that the speed is fast, but in 10g cases, Standby must be in the mount State and cannot share part of the read load for Primary (physical Standby can apply redo in the case of open in 11g ). There is also a logic Standby SQL application that parses the SQL statement through LogMiner and then runs it on the Standby end. It is obviously not fast to directly Redo the application. Redo real-time applications by default, log application service will wait for a single archive file to be received before starting the application. However, if the standby end is configured with standby redo logs, you can open the real-time apply (real-time apply), so that you do not need to wait until the archive file is received, as long as rfs writes redo data to standby redologs, you can use MRP/LSP to write data to standby in real time. [SQL] use the following statements to enable real-time applications in physical standby: SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE; use the following statements to enable real-time applications in logical standby: SQL> ALTER DATABASE START LOGICAL STANDBYAPPLY IMMEDIATE;