group and cogroup in pig

now i will load the file

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from local system to grunt

grunt> st1 = load'/home/sandeep/student'
USING PigStorage(',')as(id:int, firstname:chararray, lastname:chararray, age:int, phone:chararray, city:chararray);


i wantt to group the dataset according to age.
So i will appaly group operator

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gAge = GROUP st1 by age;

dump gAge

;

cogroup

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Normally group work with single relation where as cogroup works with multiple relation

so we
load the same daa set as 2  different dataset.

You can also load 2 diff dataset.

for convenience i take 1 dataset and stored it using 2 dif variable relation name



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st2 = load'/home/sandeep/student' USING PigStorage(',')as
(id:int, firstname:chararray, lastname:chararray, age:int, phone:chararray, city:chararray);


st3 = load'/home/sandeep/student' USING PigStorage(',')as(id:int, firstname:chararray, lastname:chararray,
age:int, phone:chararray, city:chararray);


st4 = COGROUP st2 by age, st3 by age;

dump st4

#cogroup in pig

#cogroup operator in pig in bigdata