org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators

Class JoinPackager

java.lang.Object

org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.Packager

org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.JoinPackager

All Implemented Interfaces:

Serializable, Cloneable, Illustrable

public class JoinPackager
extends Packager

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.Packager

Packager.PackageType

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_CHUNK_SIZE

Fields inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.Packager

bags, distinct, illustrator, isKeyCompound, isKeyTuple, key, keyInfo, keyType, mBagFactory, mTupleFactory, parent, readOnce

Constructor Summary

Constructors

Constructor and Description
JoinPackager(Packager p, POForEach f)

Method Summary

Modifier and Type	Method and Description
void	attachInput(Object key, DataBag[] bags, boolean[] readOnce)
POOptimizedForEach	getForEach()
List<PhysicalPlan>	getInputPlans()
Result	getNext() Calls getNext to get next ForEach result.
String	name()
void	setChunkSize(long chunkSize)
void	setIllustrator(Illustrator illustrator)
void	setInputPlans(List<PhysicalPlan> plans)
void	setToBeFlattened(List<Boolean> flattens)

Methods inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.Packager

checkBagType, clone, detachInput, getBag, getIllustrator, getInner, getKey, getKey, getKeyAsTuple, getKeyInfo, getKeyTuple, getKeyType, getNumInputs, getNumInputs, getPackageType, getUseSecondaryKey, getValueTuple, illustratorMarkup, illustratorMarkup2, isDistinct, numberOfEquivalenceClasses, setDistinct, setInner, setKeyCompound, setKeyInfo, setKeyTuple, setKeyType, setNumInputs, setPackageType, setParent, setUseSecondaryKey, starMarkup

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CHUNK_SIZE

public static final String DEFAULT_CHUNK_SIZE

See Also:

Constant Field Values

Constructor Detail

JoinPackager

public JoinPackager(Packager p,
                    POForEach f)

Method Detail

getNext

public Result getNext()
               throws ExecException

Calls getNext to get next ForEach result. The input for POJoinPackage is a (key, NullableTuple) pair. We will materialize n-1 inputs into bags, feed input#n one tuple a time to the delegated ForEach operator, the input for ForEach is (input#1, input#2, input#3....input#n[i]), i=(1..k), suppose input#n consists of k tuples. For every ForEach input, pull all the results from ForEach. getNext will be called multiple times for a particular input, it returns one output tuple from ForEach every time we call getNext, so we need to maintain internal status to keep tracking of where we are.

Overrides:

getNext in class Packager

Throws:

ExecException

attachInput

public void attachInput(Object key,
                        DataBag[] bags,
                        boolean[] readOnce)
                 throws ExecException

Overrides:

attachInput in class Packager

Throws:

ExecException

getInputPlans

public List<PhysicalPlan> getInputPlans()

setInputPlans

public void setInputPlans(List<PhysicalPlan> plans)

setToBeFlattened

public void setToBeFlattened(List<Boolean> flattens)

getForEach

public POOptimizedForEach getForEach()

Returns:

the forEach

setChunkSize

public void setChunkSize(long chunkSize)

Parameters:

chunkSize - - the chunk size for the biggest input

setIllustrator

public void setIllustrator(Illustrator illustrator)

Specified by:

setIllustrator in interface Illustrable

Overrides:

setIllustrator in class Packager

name

public String name()

Overrides:

name in class Packager