org.openanzo.glitter.query.planning
Class OdoQueryOptimizer

java.lang.Object
  org.openanzo.glitter.query.planning.OdoQueryOptimizer

All Implemented Interfaces:

QueryExecutionPlan

public class OdoQueryOptimizer
extends java.lang.Object
implements QueryExecutionPlan

The OdoQueryOptimizer attempts to prioritize evaluation of triple patterns with less free variables before those with more free variables.

Author:

Matthew Roy ( mroy@cambridgesemantics.com )

Constructor Summary

OdoQueryOptimizer()

Method Summary

java.util.Iterator<TreeNode>

orderNodes(java.util.Iterator<? extends TreeNode> nodes) Provides an execution plan by ordering a sequence of sibling nodes.

Methods inherited from class java.lang.Object

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

Constructor Detail

OdoQueryOptimizer

public OdoQueryOptimizer()

Method Detail

orderNodes

public java.util.Iterator<TreeNode> orderNodes(java.util.Iterator<? extends TreeNode> nodes)

Description copied from interface: QueryExecutionPlan

Provides an execution plan by ordering a sequence of sibling nodes.

Specified by:

orderNodes in interface QueryExecutionPlan

Parameters:

nodes - The original order of the nodes.

Returns:

An iterator over the nodes in the order in which bindings should be generated.