org.modeshape.jcr.spi.index.provider

Interface Costable

All Known Subinterfaces:

LocalIndex<T>, ManagedIndex

All Known Implementing Classes:

ManagedLocalIndex

public interface Costable

A simple interface that provides metrics needed to compute the cost of applying indexes.

Method Summary

Methods

Modifier and Type	Method and Description
long	estimateCardinality(Constraint constraint) Compute the cost applying the given constraint.
long	estimateTotalCount() Get the estimated number of entries within this index.

Method Detail

estimateCardinality

long estimateCardinality(Constraint constraint)

Compute the cost applying the given constraint.

Parameters:

constraint - the constraint; never null

Returns:

the approximate number of records that will be returned

estimateTotalCount

long estimateTotalCount()

Get the estimated number of entries within this index.

Returns:

the number of entries, or -1 if not known