The following script generates wrong result:
A = load 'A.txt' using PigStorage(',') as (id:chararray, value:double);
B = load 'B.txt' using PigStorage(',') as (id:chararray, name:chararray);
t1 = group A by id;
t2 = foreach t1
t3 = join B by id LEFT OUTER, t2 by id;
But we get:
With the option "-t PushDownForEachFlatten", the issue goes away.