(row)
return row['query_signature'], row['datname'], row['rolname']
:param row: a normalized row from pg_stat_statements
    :return: a tuple uniquely identifying this row
:param row: a normalized row from pg_stat_statements
    :return: a tuple uniquely identifying this row
: param row : a normalized row from pg_stat_statements : return : a tuple uniquely identifying this row
def _row_key(row):
    """
    :param row: a normalized row from pg_stat_statements
    :return: a tuple uniquely identifying this row
    """
    return row['query_signature'], row['datname'], row['rolname']
def _row_key ( row ) : return row [ 'query_signature' ] , row [ 'datname' ] , row [ 'rolname' ]