use DBI;
use DBD::Oracle qw(:ora_session_modes);

my $dsn = "dbi:Oracle:";
#$ENV{ORACLE_SID} = "ABCD12";
$ENV{ORACLE_SID} = "ABCD12.COMPANYDOMAIN.COM";
delete $ENV{TWO_TASK};
my $dbh = DBI->connect($dsn, "", "", { ora_session_mode => ORA_SYSDBA });