Pig Split command

============SPLIT==================

Emp1 = LOAD '/user/cloudera/N_EMP1.txt' USING PigStorage(',') as ( sno:int , name:chararray , role:chararray , salary:chararray , company:chararray , exp:int);

Emp2 = LOAD '/user/cloudera/N_EMP2.txt' USING PigStorage(',') as ( sno:int , name:chararray , role:chararray , salary:int , company:chararray , exp:int);

The SPLIT operator is used to split a relation into two or more relations.

SPLIT Emp1 into X if (exp > 3), Y if (exp < 3);

dump X;

==========CROSS========

c = CROSS Emp1,Emp2;

 dump c;

Join:

TXN = LOAD '/user/cloudera/txns.txt' USING PigStorage(',')  as (txnno:INT, txndate:CHARARRAY, custno:INT, amount:INT, category:CHARARRAY, product:CHARARRAY, city:CHARARRAY, state:CHARARRAY, spendby:CHARARRAY);

CUTS = LOAD '/user/cloudera/custs' USING PigStorage(',')  as (cusid:int, firstname: CHARARRAY, lastname: CHARARRAY, age:int,profession:CHARARRAY);

J = Join TXN by custno, CUTS by cusid;

L = Limit J 20;

DUMP L;

·       Left Outer Joins:

A left outer join means records from the left side willbe included even when they do not have a match on the right side.

LJ= JOIN F by custno LEFT OUTER, F1 by cusid;

LJ1= LIMIT LJ 15;

DUMP LJ1;

·       Right Outer Join:

A right outer joins means records from the right side will be included even when they do nothave a match on the left side.

RJ= JOIN F by custno RIGHT OUTER, F1 by cusid;

RJ1= LIMIT RJ 15;

DUMP RJ1;

·       Full Outer Join:

A full outer join means records from both sides are taken even when they do not have matches.

FJ = JOIN F by custno FULL OUTER , F1 by cusid;

DUMP FJ;

·       Self Join:

Self joins are supported, though the data must be loaded twice.

trans = LOAD '/user/cloudera/txns.txt' AS (txnno:chararray,txndate:chararray,custno:int,amount:chararray,category:chararray,product:chararray,city:chararray,state:chararray,spendby:chararray);

trans1 = LOAD '/user/cloudera/txns.txt' AS (txnno:chararray,txndate:chararray,custno:int,amount:chararray,category:chararray,product:chararray,city:chararray,state:chararray,spendby:chararray);

SF = JOIN trans by custno, trans1 by custno;

SF1= LIMIT SF 15;

DUMP SF1;