Combining & Splitting

Union Operator

grunt> Relation_name3 = UNION Relation_name1, Relation_name2;

vi ~/pig/student_data2.txt

7,Komal,Nayak,9848022334,trivendram.
8,Bharathi,Nambiayar,9848022333,Chennai.
$ hdfs dfs -put ~/pig/student_data2.txt hdfs://localhost:9000/pig_data/
grunt> student1 = LOAD 'hdfs://localhost:9000/pig_data/student_data.txt' USING PigStorage(',')
   as (id:int, firstname:chararray, lastname:chararray, phone:chararray, city:chararray);
grunt> student2 = LOAD 'hdfs://localhost:9000/pig_data/student_data2.txt' USING PigStorage(',')
   as (id:int, firstname:chararray, lastname:chararray, phone:chararray, city:chararray);
grunt> student = UNION student1, student2;
grunt> Dump student;

Split Operator

grunt> SPLIT Relation1_name INTO Relation2_name IF (condition1), Relation2_name (condition2)
grunt> student_details = LOAD 'hdfs://localhost:9000/pig_data/student_details.txt' USING PigStorage(',')
   as (id:int, firstname:chararray, lastname:chararray, age:int, phone:chararray, city:chararray);
grunt> SPLIT student_details into student_details1 if age<23, student_details2 if (22<age and age>25);
grunt> Dump student_details1;
grunt> Dump student_details2;