Pig ORDER BY Usage example

sorted = order data by $;

Numeric types are compared by numeric size chararray types are compared by the dictionary order of the characters ByteArray compare complex types in dictionary order of bytes (map, tuple, bag) cannot compare null is the smallest trigger reduce phase

sorted = Order data by $0;sorted = Order data by $ DESC, ASC;

　　

The order by is a global sort, there is a reduce phase, there is the possibility of data skew, in order to solve this problem, pig in the shuffle process using a splitter , according to the sampling results of the data is relatively evenly distributed to the reducer, The disadvantage of this is that the data corresponding to the same sort key may be stored in different files.

Pig ORDER BY Usage example