$$database_handle = DBI->connect(
                     map {
                             my $s = "database_$_";
                             exists $arguments{$_} ?
                                    $arguments{$_}  :
                                    $s->()
                     }
                     qw(data_source_name username password
                        taint)
                ) or die "Could not connect to the ".
                         "database: $DBI::errstr";