my $batchsize = 20; # tune this value
my $count = 0;
my $sth = $dbh->prepare('update myTable set va = ?, vb = ? where vc = ?');
$dbh=>begin_work; # or however you start a transaction; don't take my word on this line
while (my $record = <$input>)
{
    chomp $record;
    my ($va, $vb, $vc) = (split(/\|/, $record))[1, 3, 5};
    $sth->execute($va, $vb, $vc);
    
    $count += 1;
    if ($count % $batchsize == 0)
    {
        $dbh->commit;     # doublecheck the commit statement too
        $dbh->begin_work;
    }
}