com.bigdata.rdf.sparql.ast.optimizers

Class AskOptimizer

java.lang.Object

com.bigdata.rdf.sparql.ast.optimizers.AskOptimizer

All Implemented Interfaces:

IASTOptimizer

public class AskOptimizer
extends Object
implements IASTOptimizer

ASK queries have a LIMIT of ONE imposed unless they are aggregations. TODO ASK style aggregations should always succeed (unless they encounter an error) and could be refactored into a subquery with a limit of ONE and an aggregation to ensure that they do the minimum possible work.

Constructor Summary

Constructors

Constructor and Description
AskOptimizer()

Method Summary

Methods

Modifier and Type	Method and Description
QueryNodeWithBindingSet	optimize(AST2BOpContext context, QueryNodeWithBindingSet input) Optimize the AST.

Methods inherited from class java.lang.Object

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

Constructor Detail

AskOptimizer

public AskOptimizer()

Method Detail

optimize

public QueryNodeWithBindingSet optimize(AST2BOpContext context,
                               QueryNodeWithBindingSet input)

Description copied from interface: IASTOptimizer

Optimize the AST.

Specified by:

optimize in interface IASTOptimizer

Parameters:

context - The evaluation context.

input - The input to the optimizer, consisting of a queryNode and input binding set.

Returns:

An instance of type QueryNodeWithBindingSet.