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.)})