com.bigdata.bop.joinGraph

Class DefaultRangeCountFactory

java.lang.Object

com.bigdata.bop.joinGraph.DefaultRangeCountFactory

All Implemented Interfaces:

IRangeCountFactory

public class DefaultRangeCountFactory
extends Object
implements IRangeCountFactory

Default implementation.

Version:

$Id$

Author:

Bryan Thompson

Field Summary

Fields

Modifier and Type	Field and Description
protected static boolean	DEBUG
protected static org.apache.log4j.Logger	log

Constructor Summary

Constructors

Constructor and Description
DefaultRangeCountFactory(IJoinNexus joinNexus)

Method Summary

Methods

Modifier and Type	Method and Description
long	rangeCount(IPredicate predicate) Return the range count for the predicate.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final transient org.apache.log4j.Logger log

DEBUG

protected static final transient boolean DEBUG

Constructor Detail

DefaultRangeCountFactory

public DefaultRangeCountFactory(IJoinNexus joinNexus)

Method Detail

rangeCount

public long rangeCount(IPredicate predicate)

Return the range count for the predicate. The range counts are requested using the "non-exact" range count query, so the range counts are actually the upper bound. However, if the upper bound is ZERO (0) then the range count really is ZERO (0).

Specified by:

rangeCount in interface IRangeCountFactory

Parameters:

tailIndex - The index of the predicate in the tail of the rule.

Returns:

The range count for that tail predicate.