com.bigdata.bop.joinGraph

Interface IRangeCountFactory

All Known Implementing Classes:

DefaultRangeCountFactory

public interface IRangeCountFactory

An interface used by an IEvaluationPlan to obtain range counts for the IPredicates in an IRule. The use of this interface on the one hand makes it possible to test IEvaluationPlans without real data and on the other hand makes it possible to cache range counts across queries evaluated against the same state of the database.

Version:

$Id$

Author:

Bryan Thompson

Method Summary

Methods

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

Method Detail

rangeCount

long rangeCount(IPredicate pred)

Return the range count for the predicate as bound. For indices that use delete markers this will be an upper bound NOT an exact range count. However, if the range count is reported as ZERO (0L) as an upper bound this still indicates that there are no solutions for that predicate in the data.

Parameters:

pred - The predicate.

Returns:

The range count.