org.modeshape.jcr.spi.index.provider

Interface Costable

All Known Subinterfaces:

ManagedIndex, ProvidedIndex<T>

All Known Implementing Classes:

DefaultManagedIndex, EsIndex, LocalIndex, LuceneIndex

public interface Costable

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

Method Summary

Modifier and Type	Method and Description
long	estimateCardinality(List<Constraint> andedConstraints, Map<String,Object> variables) Compute the cost applying the given constraints joined together conceptually using AND.
long	estimateTotalCount() Get the estimated number of entries within this index.

Method Detail

estimateCardinality

long estimateCardinality(List<Constraint> andedConstraints,
                         Map<String,Object> variables)

Compute the cost applying the given constraints joined together conceptually using AND.

Parameters:

andedConstraints - the constraints; never null

variables - the bound variables for the query that is being costed; 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