datafu.pig.bags

Class ZipBags

java.lang.Object

org.apache.pig.EvalFunc<org.apache.pig.data.DataBag>

datafu.pig.bags.ZipBags

public class ZipBags
extends org.apache.pig.EvalFunc<org.apache.pig.data.DataBag>

This udf takes any number of bags and allows you to zip them into one bag with the tuples inside each bag concatenated to each other. Example:

 -- input:
 -- ({(1,2),(3,4),(5,6)},{(7,8),(9,10),(11,12)})
 input = LOAD 'input' AS (OUTER: tuple(B1: bag {a:INT,b:INT}, B2: bag{c:INT,d:INT}));

 -- output:
 -- ({(1,2,7,8),(3,4,9,10),(5,6,11,12)})
 k
 output = FOREACH input GENERATE ZipBags(B1,B2);
 
 

For this to work as expected each bag should be the same length. It will run as long as the first bag is the shortest however this may not be the desired behavior.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.pig.EvalFunc

org.apache.pig.EvalFunc.SchemaType

Field Summary

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

Constructors

Constructor and Description
ZipBags()

Method Summary

Methods

Modifier and Type	Method and Description
org.apache.pig.data.DataBag	exec(org.apache.pig.data.Tuple input)
org.apache.pig.impl.logicalLayer.schema.Schema	outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input)

Methods inherited from class org.apache.pig.EvalFunc

allowCompileTimeCalculation, finish, getArgToFuncMapping, getCacheFiles, getInputSchema, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, getSchemaType, getShipFiles, isAsynchronous, progress, setInputSchema, setPigLogger, setReporter, setUDFContextSignature, warn

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ZipBags

public ZipBags()

Method Detail

exec

public org.apache.pig.data.DataBag exec(org.apache.pig.data.Tuple input)
                                 throws java.io.IOException

Specified by:

exec in class org.apache.pig.EvalFunc<org.apache.pig.data.DataBag>

Throws:

java.io.IOException

outputSchema

public org.apache.pig.impl.logicalLayer.schema.Schema outputSchema(org.apache.pig.impl.logicalLayer.schema.Schema input)

Overrides:

outputSchema in class org.apache.pig.EvalFunc<org.apache.pig.data.DataBag>