with median as (select lat_n, row_number () over (order by lat_n asc) as row_asc,row_number () over (order by lat_n desc) as row_desc from station ) select round(avg(lat_n),4) from median where abs(row_asc-row_desc) <= 1 ERROR 1690 (22003) at line 1: BIGINT UNSIGNED value is out of range in '(median.row_asc - median.row_desc)' while doin the same in postgresql the error shows- ERROR: function round(double precision, integer) does not exist LINE 7: select round(avg(lat_n),4) ^ HINT: No function matches the given name and argument types. You might need to add explicit type casts. SQL state: 42883 Character: 152