com.bigdata.relation.rule

Interface IAccessPathExpander<E>

All Superinterfaces:

Serializable

All Known Implementing Classes:

DGExpander, EmptyAccessPathExpander

public interface IAccessPathExpander<E>
extends Serializable

An interface for expander patterns for an IPredicate when it appears in the right-hand position of a JOIN.

Version:

$Id$

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
boolean	backchain() Deprecated. Never true. The backchainer is only run for normal predicates in triples mode at this time. If it is to be layer, it should be layered as an annotation. See https://sourceforge.net/apps/trac/bigdata/ticket/231.
IAccessPath<E>	getAccessPath(IAccessPath<E> accessPath) Return the IAccessPath that will be used to evaluate the IPredicate.
boolean	runFirst() If true, the predicate for this expander will be given priority in the join order.

Method Detail

getAccessPath

IAccessPath<E> getAccessPath(IAccessPath<E> accessPath)

Return the IAccessPath that will be used to evaluate the IPredicate.

Parameters:

accessPath - The IAccessPath that will be used by default.

Returns:

The IAccessPath that will be used. You can return the given accessPath or you can layer additional semantics onto or otherwise override the given IAccessPath.

backchain

boolean backchain()

Deprecated. Never true. The backchainer is only run for normal predicates in triples mode at this time. If it is to be layer, it should be layered as an annotation. See https://sourceforge.net/apps/trac/bigdata/ticket/231.

Add the backchainer on top of the expander.

Returns:

true if the backchainer should run

runFirst

boolean runFirst()

If true, the predicate for this expander will be given priority in the join order.

Returns:

true if the predicate should be run first