org.xcmis.search.query.optimize
Class CriteriaBasedOptimizer

java.lang.Object
  org.xcmis.search.query.optimize.CriteriaBasedOptimizer

All Implemented Interfaces:

Optimizer

public class CriteriaBasedOptimizer
extends Object
implements Optimizer

Optimizer implementation that optimizes a query using a stack of rules. Subclasses can override the populateCriteriaStack(LinkedList, QueryExecutionPlan) method to define the stack of criteria they'd like to use, including the use of custom criteria's.

Constructor Summary

CriteriaBasedOptimizer()

Method Summary

QueryExecutionPlan	optimize(QueryExecutionContext context, QueryExecutionPlan plan) Optimize the supplied query plan and produce an executable processor plan.
protected void	populateCriteriaStack(LinkedList<OptimizerCriteria> criteriaStack, QueryExecutionPlan plan) Method that is used to create the initial criteria stack.

Methods inherited from class java.lang.Object

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

Constructor Detail

CriteriaBasedOptimizer

public CriteriaBasedOptimizer()

Method Detail

optimize

public QueryExecutionPlan optimize(QueryExecutionContext context,
                                   QueryExecutionPlan plan)

Description copied from interface: Optimizer

Optimize the supplied query plan and produce an executable processor plan.

Specified by:

optimize in interface Optimizer

Parameters:

context - the context in which the query is being optimized

plan - the query plan to be optimized

Returns:

the optimized query plan; never null

See Also:

Optimizer.optimize(org.xcmis.search.query.QueryExecutionContext, org.xcmis.search.query.plan.QueryExecutionPlan)

populateCriteriaStack

protected void populateCriteriaStack(LinkedList<OptimizerCriteria> criteriaStack,
                                     QueryExecutionPlan plan)

Method that is used to create the initial criteria stack. This method can be overridden by subclasses

Parameters:

ruleStack - the stack where the rules should be placed; never null

hints - the plan hints