$ file /opt/oracle/app/oracle/product/10g/perl/lib/site_perl/5.8.3/i686-linux-thread-multi/auto/DBD/Oracle/Oracle.so
$ file /opt/oracle/11g/perl/lib/site_perl/5.8.3/i686-linux-thread-multi/auto/DBD/Oracle/Oracle.so
$ file `which perl`
$ perl -v

examples

64bit system:

$ locate Oracle.so | xargs file
/pro/3gl/CPAN/DBD-Oracle-svn/blib/arch/auto/DBD/Oracle/Oracle.so:          ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=0x634e4eeda1913e3bcc82e83683476ddf93e2d68b, not stripped
/pro/lib/perl5/site_perl/5.14.1/x86_64-linux-ld/auto/DBD/Oracle/Oracle.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=0x672b28a177525e87ea79511e7308a00a4253a3b1, not stripped
/pro/lib/perl5/site_perl/5.16.2/x86_64-linux-ld/auto/DBD/Oracle/Oracle.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=0x9b78d14ec3db186add1217b873eb6e0e244b15d8, not stripped
$ file `which perl`
/pro/bin/perl5.16.2: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=0x6141d33c4fed73f117265c8980077086a63f4ea9, not stripped
$ ldd /pro/lib/perl5/site_perl/5.16.2/x86_64-linux-ld/auto/DBD/Oracle/Oracle.so
        linux-vdso.so.1 (0x00007fff58bff000)
        libocci.so.11.1 => /usr/lib/oracle/11.2/client64/lib/libocci.so.11.1 (0x00007f7cca5da000)
        libclntsh.so.11.1 => /usr/lib/oracle/11.2/client64/lib/libclntsh.so.11.1 (0x00007f7cc7d48000)
        libpthread.so.0 => /lib/../lib64/libpthread.so.0 (0x00007f7cc7b2c000)
        libc.so.6 => /lib/../lib64/libc.so.6 (0x00007f7cc7787000)
        libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00007f7cc7455000)
        libm.so.6 => /lib64/libm.so.6 (0x00007f7cc715e000)
        libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f7cc6f48000)
        libnnz11.so => not found
        libdl.so.2 => /lib64/libdl.so.2 (0x00007f7cc6d43000)
        libnsl.so.1 => /lib64/libnsl.so.1 (0x00007f7cc6b2b000)
        libaio.so.1 => /lib64/libaio.so.1 (0x00007f7cc6928000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f7ccaa6d000)
$ file /usr/lib/oracle/11.2/client64/lib/libocci.so
/usr/lib/oracle/11.2/client64/lib/libocci.so: symbolic link to `libocci.so.11.1'

32bit system:

$ locate Oracle.so | xargs file
/pro/lib/perl5/site_perl/5.10.0/i686-linux-64int/auto/DBD/Oracle/Oracle.so:    ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, not stripped
/pro/lib/perl5/site_perl/5.12.2/i686-linux-64int-ld/auto/DBD/Oracle/Oracle.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, BuildID[sha1]=0xffc084157f97d79089c90edc0a6ad681bf13cca2, not stripped
/pro/lib/perl5/site_perl/5.14.1/i686-linux-64int-ld/auto/DBD/Oracle/Oracle.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, BuildID[sha1]=0x4acbc12ed8f3024310e8b4d43003e05e8262f98d, not stripped
/pro/lib/perl5/site_perl/5.16.3/i686-linux-64int/auto/DBD/Oracle/Oracle.so:    ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, BuildID[sha1]=0x3de5f5ea3f207001b31657f00b5dfc7359a072da, not stripped
/pro/lib/perl5/site_perl/5.18.0/i686-linux-64int-ld/auto/DBD/Oracle/Oracle.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, BuildID[sha1]=0xf68f6a584bf07363d640c8c7a8b7a093e987cbd9, not stripped
$ file `which perl`
/pro/bin/perl5.18.0: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.16, BuildID[sha1]=0xf4d0718a75c0dbe0d874f0575a4e415a1e6ad96c, not stripped
$  ldd /pro/lib/perl5/site_perl/5.18.0/i686-linux-64int-ld/auto/DBD/Oracle/Oracle.so
        linux-gate.so.1 (0xb7791000)
        libocci.so.11.1 => /usr/lib/oracle/11.2/client/lib/libocci.so.11.1 (0xb7605000)
        libclntsh.so.11.1 => /usr/lib/oracle/11.2/client/lib/libclntsh.so.11.1 (0xb560b000)
        libpthread.so.0 => /lib/libpthread.so.0 (0xb55b7000)
        libc.so.6 => /lib/libc.so.6 (0xb543d000)
        libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0xb5350000)
        libm.so.6 => /lib/libm.so.6 (0xb530e000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb52f0000)
        libnnz11.so => not found
        libdl.so.2 => /lib/libdl.so.2 (0xb52eb000)
        libnsl.so.1 => /lib/libnsl.so.1 (0xb52d1000)
        libaio.so.1 => /lib/libaio.so.1 (0xb52ce000)
        /lib/ld-linux.so.2 (0xb7792000)
$ file /usr/lib/oracle/11.2/client/lib/libocci.so.11.1
/usr/lib/oracle/11.2/client/lib/libocci.so.11.1: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked, not stripped