Alert log file

<alert<SID>.log>

alert.log file contains the following information :

1.The data & the timestamp when the database was opened & closed.

2.Log Sequence numbers.

3.All explicit init.ora parameters.

4.The instance startup process.

5.The Background process startup sequence.

6.Create tablespace commands

7.Alter database commands.

8.ORA related error messages(like ORA - 600, ORA - 60 etc)

9.Warning messages.

Note : If we loose the alert log file, nothing happens to the database and it will be created automatically.

 

During some operations of the database, some entries will be placed in the alert log & the alert log file size grows & the size becomes unmanagable.

As a DBA, we need to peroform some maintainance activity on the alert log file(like weekly once/15 days once/monthly once etc), occasionally we need to take the backup of the alert log & delete the alert log file. Once we delete, oracle creates automatically.