com.lucidera.opt
Class LoptMultiJoin.RemovableSelfJoin

java.lang.Object
  com.lucidera.opt.LoptMultiJoin.RemovableSelfJoin

Enclosing class:

LoptMultiJoin

private class LoptMultiJoin.RemovableSelfJoin
extends Object

Utility class used to keep track of the factors in a removable self-join. The right factor in the self-join is the one that will be removed.

Field Summary

private Map<Integer,Integer>	columnMapping A mapping that maps references to columns from the right factor to columns in the left factor, if the column is referenced in both factors
private int	leftFactor The left factor in a removable self-join
private int	rightFactor The right factor in a removable self-join, namely the factor that will be removed

Constructor Summary

LoptMultiJoin.RemovableSelfJoin(int leftFactor, int rightFactor, Map<Integer,Integer> columnMapping)

Method Summary

Map<Integer,Integer>	getColumnMapping()
int	getLeftFactor()
int	getRightFactor()

Methods inherited from class java.lang.Object

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

Field Detail

leftFactor

private int leftFactor

The left factor in a removable self-join

rightFactor

private int rightFactor

The right factor in a removable self-join, namely the factor that will be removed

columnMapping

private Map<Integer,Integer> columnMapping

A mapping that maps references to columns from the right factor to columns in the left factor, if the column is referenced in both factors

Constructor Detail

LoptMultiJoin.RemovableSelfJoin

LoptMultiJoin.RemovableSelfJoin(int leftFactor,
                                int rightFactor,
                                Map<Integer,Integer> columnMapping)

Method Detail

getLeftFactor

public int getLeftFactor()

getRightFactor

public int getRightFactor()

getColumnMapping

public Map<Integer,Integer> getColumnMapping()