use DBI;

$ENV{ORACLE_HOME} = '/usr/local/oracle/OraHome_1';

# Database connection data
my $dsn = "DBI:Oracle:host=$host;sid=$sid";
my $user = 'luser';
my $password = 's3c3t';

my $dbh = DBI->connect($dsn, $user, $password)
   or die "Can't connect: $DBI::errstr";

...