How to check Oracle Software is 32-Bit or 64-Bit

On a Linux system

$cd $ORACLE_HOME/bin 

$file oracle

For example on Redhat Linux
 $file oracle

 oracle: setuid setgid ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, not stripped 


Also you can check by connecting to server as sysdba

$ sqlplus "/as sysdba"

SQL*Plus: Release 11.2.0.4.0 Production on Thu Jul 9 16:07:16 2015

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

--- Third way of checking

sql>select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi
PL/SQL Release 10.2.0.4.0 - Production
CORE    10.2.0.4.0      Production
TNS for Solaris: Version 10.2.0.4.0 - Production
NLSRTL Version 10.2.0.4.0 - Production







The examples above show that the Oracle database software version is 64-bit. If the software is 32-bit, then "64bit" would not be present in either example above.

SQL>select distinct(length(addr)*4) "Word Size" from v$process;

 Word Size
----------
        64  


On 32 bit systems it shows 32

SQL>select distinct(length(addr)*4) "Word Size" from v$process;

 Word Size
----------
        32