Alert log

The alert log file (also referred to as the ALERT.LOG) is a chronological log of messages and errors written out by an Oracle Database. Typical messages found in this file is: database startup, shutdown, log switches, space errors, etc. This file should constantly be monitored to detect unexpected messages and corruptions.

Oracle will write the alert.log file to the directory as specified by the BACKGROUND_DUMP_DEST parameter.

In Oracle 10g

SQL> show parameter BACKGROUND_DUMP_DEST

NAME                         TYPE            VALUE

------------------------- -----------   -------------------------------

background_dump_dest         string    /u01/user10/demo/bdump/alert.log

SQL> show parameter BACKGROUND_DUMP_DEST

In Oracle 11g

SQL> show parameter BACKGROUND_DUMP_DEST

NAME                        TYPE        VALUE

------------------------- ----------- ------------------------------

background_dump_dest        string      /app/oracle/diag/rdbms/o11gr1/

                                        trace