Ways to check the version of an Oracle Database

WAY 1 (Using the v$version view)
SQL> select * from v$version;


BANNER
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Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
PL/SQL Release 11.1.0.6.0 - Production
CORE    11.1.0.6.0      Production
TNS for 32-bit Windows: Version 11.1.0.6.0 - Production
NLSRTL Version 11.1.0.6.0 - Production

WAY 2 ( When you connect to the database)

C:\Documents and Settings\WELCOME>sqlplus '/ as sysdba'

SQL*Plus: Release 11.1.0.6.0 - Production on Sat Jan 29 18:44:08 2011

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

Enter password:

Connected to:

Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options