ccity = load 'worldcitiespop.txt' using PigStorage(',') as (ccode:chararray, cityName:chararray, cityFullName:chararray, region:int, population:long, lat:double, long:double);
 groupCcityByCcode = group cCity by ccode;
 cityWithHighestPopulation = foreach groupCcityByCcode {
                                 citiesWithPopulation = filter cCity by (population is not null AND population > 0);
                                 orderCitiesWithPopulation = order citiesWithPopulation by population desc;
                                 topPopulousCity = limit orderCitiesWithPopulation 1;
                                 generate flatten(topPopulousCity); };
 
 
