my $sth = $dbh->prepare("select name from file_table where <some condition>");
my $upd_sth = $dbh->prepare("update file_table set timestamp = ? where name = ?");

while(my $d = $sth->fetch) {
    # do the upload, etc;
    # if all is well:
    $sth_upd->execute(time, $d->[0]);
}