alter database force logging 含义

Oracle Dataguard
Chapter 3 - Implementing Standby Databases

Preparing To Create a Physical Standby Database

ALTER DATABASE ARCHIVELOG;

If the “automatic archival” is not enabled, it can be enabled using the following statement:

ALTER SYSTEM ARCHIVE LOG START;

Change the log_archive_start=true parameter in the initialization file so that it will remain enabled on next startup of the database.  

Once the database is in archive log mode, the next step is to put it in FORCE LOGGING mode. This will ensure that all the transactions made on the primary database will be registered in the redo logs of the primary database and can be replicated on standby databases.

FORCE LOGGING Option

The FORCE LOGGING option is the safest method to ensure that all the changes made in the database will be captured and available for recovery in the redo logs. Force logging is the new feature added to the family of logging attributes.

Before the existence of FORCE LOGGING, Oracle provided logging and nologging options. These two options have higher precedence at the schema object level than the tablespace level; therefore, it was possible to override the logging settings at the tablespace level with nologging setting at schema object level.

rollping :

就是说，设置FORCE LOGGING 之后。本来一些可以指定nologging减少redo log的操作 ，虽然不报错，但事实上redo log还是都纪录了。
等于是，没法nologging了

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