Can't locate object method "prepare" via package "dbh" - Error

[Ajay Madan]

Hi,

        I recently tested and installed the DBI and DBD:Oracle modules.I am a beginner 
to using
DBI to connect to the Database. My first task is to connect to an Oracle Database 
using a 7.3.4
Oracle Client, with the SQL statement as "SELECT * FROM TAB"

My program is as follows:

#!/usr/local/bin/perl

use DBI;

my $dbuser = $ENV{ORACLE_USERID} || 's1_gwy/s1_gwy01';
my $dbh = DBI->connect('DBI:Oracle:', $dbuser, '')
                or die "Couldnt connect to database: " . DBI->errstr;
my $sth = dbh->prepare('SELECT * FROM TAB')
                or die "Couldn't prepare statement: " . $dbh->errstr;
$sth->execute or die "Couldnt execute statement: " . $sth->errstr;
$dbh->disconnect;

When I executed the above piece of code I got the following error:

Can't locate object method "prepare" via package "dbh" at ./fpgm2db line 9.

The PATH, LD_LIBRARY_PATH, TWO_TASK, ORACLE_HOME env variabes are set to proper
values. Could this problem be because, although my Oralce Home points to 7.3.4, I am 
using
8.0.5's lib directory(for LD_LIBRARY_PATH). But I did that, because I get an error if 
I try to use
7.3.4's lib.

Need your help, to get started in the DBI World :-)

Thanks in advance,

Ajay

Versions:

DBI - 1.15
DBD - 1.06
Perl - 5.004_04
OS - Sun OS 5.6