use threads ();
use DBI;
use DBD::Oracle;

my $thrds=25;
my $iter=11;
my @threads;

for (my $j=0; $j<$iter; $j++) {
    &start($j);
}

sub start {
    my $k=$_[0];
    for (my $i=0; $i<$thrds; $i++) {
        $threads[$i] = threads->new(\&RunThread,$k, $i);
    }
    for (my $i=0; $i<$thrds; $i++) { $threads[$i]->join; }
}

sub RunThread {
    my $dbh = DBI->connect("dbi:Oracle:ora", "user","pass") or die "failed connect";
    my ($x, $y)=@_;
    open (my $fh2, ">/tmp/da-$x-$y") or die "failed in thread $! at iter $x thread $y " ;
    close ($fh2);
    $dbh->disconnect or die "disconnect failed";
}