If you need to check ORACLE’s “Alert Log” and you don’t want to use SQLPLUS or you don’t have Authorization to connect ORACLE database then you can use the following ways to do this..

From OS Level ;

- Start the tool “ADRCI” from Command Prompt

C:\>adrci

ADRCI: Release 11.2.0.3.0 – Production on Thu Sep 4 14:17:49 2014

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

ADR base = “F:\oracle\SID\saptrace”

adrci> show alert

Choose the alert log from the following homes to view:

1: diag\rdbms\<sid>\<sid>
2: diag\tnslsnr\<servername>\listener
Q: to quit

Please select option: 1
Output the results to file: C:\Users\<sid>adm\AppData\Local\Temp\alert_12640_11804_<sid>_1.ado

Alert.Log output will be open after the selection execution ;

From SAP Level ;

Go to transcation code SP12

Performance –> Additional Functions –> Alert Log

EXECUTE

Thats it..