def get_2Dtile_area(db, table_index):
    """Get the area of a 2D tile.

    Note
    ----
    Assumes that all tiles have equal area. Area is in units of the tile CRS.

    Parameters
    ----------
    db : db Class instance
    table_index : list of str
        {'schema' : str, 'table' : str} of the table of tile index.

    Returns
    -------
    float

    """
    schema = sql.Identifier(table_index['schema'])
    table = sql.Identifier(table_index['table'])

    query = sql.SQL("""
                SELECT public.st_area(geom) AS area
                FROM {schema}.{table}
                LIMIT 1;
                """).format(schema=schema, table=table)
    area = db.getQuery(query)[0][0]

    return(area)