org.apache.drill.exec.physical.impl.join

Class JoinTemplate

java.lang.Object

org.apache.drill.exec.physical.impl.join.JoinTemplate

All Implemented Interfaces:

JoinWorker

public abstract class JoinTemplate
extends Object
implements JoinWorker

Merge Join implementation using RecordIterator.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.drill.exec.physical.impl.join.JoinWorker

JoinWorker.JoinOutcome

Field Summary

Fields inherited from interface org.apache.drill.exec.physical.impl.join.JoinWorker

TEMPLATE_DEFINITION

Constructor Summary

Constructors

Constructor and Description
JoinTemplate()

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract int	doCompare(int leftIndex, int rightIndex) Compare the values of the left and right join key to determine whether the left is less than, greater than or equal to the right.
abstract void	doCopyLeft(int leftIndex, int outIndex) Copy the data to the new record batch (if it fits).
abstract void	doCopyRight(int rightIndex, int outIndex)
boolean	doJoin(JoinStatus status) Copy rows from the input record batches until the output record batch is full
abstract void	doSetup(FragmentContext context, JoinStatus status, VectorContainer outgoing)
void	setupJoin(FragmentContext context, JoinStatus status, VectorContainer outgoing)

Methods inherited from class java.lang.Object

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

Constructor Detail

JoinTemplate

public JoinTemplate()

Method Detail

setupJoin

public void setupJoin(FragmentContext context,
             JoinStatus status,
             VectorContainer outgoing)
               throws SchemaChangeException

Specified by:

setupJoin in interface JoinWorker

Throws:

SchemaChangeException

doJoin

public final boolean doJoin(JoinStatus status)

Copy rows from the input record batches until the output record batch is full

Specified by:

doJoin in interface JoinWorker

Parameters:

status - State of the join operation (persists across multiple record batches/schema changes)

Returns:

true of join succeeded; false if the worker needs to be regenerated

doSetup

public abstract void doSetup(@Named(value="context")
           FragmentContext context,
           @Named(value="status")
           JoinStatus status,
           @Named(value="outgoing")
           VectorContainer outgoing)
                      throws SchemaChangeException

Throws:

SchemaChangeException

doCopyLeft

public abstract void doCopyLeft(@Named(value="leftIndex")
              int leftIndex,
              @Named(value="outIndex")
              int outIndex)

Copy the data to the new record batch (if it fits).

Parameters:

leftIndex - position of batch (lower 16 bits) and record (upper 16 bits) in left SV4

outIndex - position of the output record batch

doCopyRight

public abstract void doCopyRight(@Named(value="rightIndex")
               int rightIndex,
               @Named(value="outIndex")
               int outIndex)

doCompare

protected abstract int doCompare(@Named(value="leftIndex")
            int leftIndex,
            @Named(value="rightIndex")
            int rightIndex)

Compare the values of the left and right join key to determine whether the left is less than, greater than or equal to the right.

Parameters:

leftIndex -

rightIndex -

Returns:

0 if both keys are equal -1 if left is < right 1 if left is > right