Max/Min for whole sets of records in PIG

Question

I have a set set of records that I am loading from a file and the first thing I need to do is get the max and min of a column. In SQL I would do this with a subquery like this:

Answer 1

As you said you need to group all the data together but no extra column is required if you use GROUP ALL.

Pig

records = LOAD 'states.txt'  AS (state:chararray, population:int);
records_group = GROUP records ALL;
with_max = FOREACH records_group 
           GENERATE
               FLATTEN(records.(state, population)), MAX(records.population);

Input

CA  10
VA  5
WI  2

Output

(CA,10,10)
(VA,5,10)
(WI,2,10)