/* * ModeShape (http://www.modeshape.org) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * This package contains the Optimizer interface, a rule-based optimizer implementation, and library of optimization rules. * The Optimizer is responsible for evaluating, validating, and manipulating a canonical query plan to produce a more * a single optimized query processing plan. The query plan is often changed in situ, although this is not required * of the {@link org.modeshape.jcr.query.optimize.Optimizer} implementations. A library of existing * {@link org.modeshape.jcr.query.optimize.OptimizerRule} classes is provided, though it's very easy to * add more optimizer rules. * </p> * <p> * The {@link org.modeshape.jcr.query.optimize.RuleBasedOptimizer} is an implementation that optimizes a query * using a stack of rules. A new stack is created for each rule, though the rules are required to be immutable and thus * often shared and reused. And, the RuleBasedOptimizer is easily subclassed to define a custom stack of rules. * </p> */ package org.modeshape.jcr.query.optimize;