PIG left, right outer joins error

PIG left, right outer joins error

  5:09 PM    ssaikgame

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We know that, we can perform JOIN operation using pig, as well as left outer join, right outer join. sometimes you'll face error when working of left and right outer joins, but not to inner joins. that is because of schema.

Even if there is no schema can perform inner join, but not for left and right outer joins.

Left, right, outer joins will not be executed without well-defined bag schema. 

Left Join: Example, the below left join will not work, but

The following left join will work, because it has schema.

grunt> emp = load 'emp.txt' using PigStorage('|') as  (eid:int,name:chararray,sal:bytearray);

grunt> dept = load 'dept.txt' using PigStorage('|') as (did:int,eid:int,name:chararray);

grunt> ljoin = join emp by eid left,dept by eid;

grunt> dump ljoin;

Right Join:

grunt> rjoin = join emp by eid right,dept by eid;

grunt> dump rjoin;