Oracle database archiving in a detailed

What is Oracle archive mode? The Oracle database has an online redo log, which records changes made to the database, such as inserting, deleting, updating data, etc., which are recorded in the online redo log. A generic database must have at least 2 online redo log groups. When an online redo log group is written full, a log switch occurs, the online redo log Group 2 becomes the currently used log, when the online redo log Group 2 is full, the log switch, to write online redo log Group 1, so repeated.

If the database is in non-archive mode, the online log is discarded when it switches. In archive mode, when a log switch occurs, the log that is toggled is archived. For example, in the current use of online redo log 1, when 1 is full, a log switch occurs, start to write online redo log 2, the contents of online redo log 1 will be copied to another specified directory. This directory is called the Archive directory, and the copied files are called archive redo logs.

First, check whether it is an archive mode

Select Name,log_mode from V$database;

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Log_mode shown as Archivelog for archive mode, noarchivelog as non-archive mode

Second, open the archive mode

1. You need to close the database before enabling the archive mode

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2. After shutting down, start the database for easy loading: start with Mount form

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3. Change the database log mode to archive mode

ALTER DATABASE Archivelog;

4. Confirm that the changes have been made

ALTER DATABASE open;

Archive log list;

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Third, close the archive mode

Archive mode changed to non-archive mode: Super Administrator login sys execution:

Shutdown immediate;

startup Mount;

Alter system archive log stop;

ALTER DATABASE Noarchivelog;

Prevent archiving online redo logs: Convert the archive mode of the database.

ALTER DATABASE open;

Open Database

Archive log list;

View archived information for connected instances;

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Oracle database archiving in a detailed