What is Alert Log?

Each database has a special file named alert_sid.log. The alert log of a database is a chronological log of messages and errors, and includes the following items:


1)All internal errors (ORA-600), block corruption errors (ORA-1578), and deadlock errors (ORA-60) that occur.

2)Administrative operations, such as CREATE, ALTER, and DROP statements and STARTUP, SHUTDOWN, and ARCHIVELOG statements.

3)Messages and errors relating to the functions of shared server and dispatcher processes.

4)Errors occurring during the automatic refresh of a materialized view.

5)The values of all initialization parameters that had nondefault values at the time the database and instance start.


Oracle Database uses the alert log to record these operations as an alternative to displaying the information on an operator's console.

The alert log file destination is specified by BACKGROUND_DUMP_DEST.