Pig Latin – Eval Functions:

AVG, CONCAT:

C = FOREACH B GENERATE A.name, AVG(A.gpa);

X = FOREACH A GENERATE CONCAT(f2,f3);

COUNT:

X = FOREACH B GENERATE COUNT(A);

Other Eval functions are

DIFF – Compares two fields in a tuple.

IsEmpty – Checks if a bag or map is empty.

Max – To get the highest value.

Min – To get the lowest value.

TOKENIZE:

Splits a string and outputs a bag of words.

A  = LOAD 'data' AS (f1:chararray);



DUMP A;

(Here is the first string.)

(Here is the second string.)

(Here is the third string.)



X = FOREACH A GENERATE TOKENIZE(f1);



DUMP X;

({(Here),(is),(the),(first),(string.)})

({(Here),(is),(the),(second),(string.)})

({(Here),(is),(the),(third),(string.)})