| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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. |
| |
| package org.apache.impala.rewrite; |
| |
| import org.apache.impala.analysis.Analyzer; |
| import org.apache.impala.analysis.BetweenPredicate; |
| import org.apache.impala.analysis.BinaryPredicate; |
| import org.apache.impala.analysis.CompoundPredicate; |
| import org.apache.impala.analysis.Expr; |
| import org.apache.impala.analysis.Predicate; |
| |
| /** |
| * Rewrites BetweenPredicates into an equivalent conjunctive/disjunctive |
| * CompoundPredicate. |
| * It can be applied to pre-analysis expr trees and therefore does not reanalyze |
| * the transformation output itself. |
| * Examples: |
| * A BETWEEN X AND Y ==> A >= X AND A <= Y |
| * A NOT BETWEEN X AND Y ==> A < X OR A > Y |
| */ |
| public class BetweenToCompoundRule implements ExprRewriteRule { |
| public static ExprRewriteRule INSTANCE = new BetweenToCompoundRule(); |
| |
| @Override |
| public Expr apply(Expr expr, Analyzer analyzer) { |
| if (!(expr instanceof BetweenPredicate)) return expr; |
| BetweenPredicate bp = (BetweenPredicate) expr; |
| Expr result = null; |
| if (bp.isNotBetween()) { |
| // Rewrite into disjunction. |
| Predicate lower = new BinaryPredicate(BinaryPredicate.Operator.LT, |
| bp.getChild(0), bp.getChild(1)); |
| Predicate upper = new BinaryPredicate(BinaryPredicate.Operator.GT, |
| bp.getChild(0), bp.getChild(2)); |
| result = new CompoundPredicate(CompoundPredicate.Operator.OR, lower, upper); |
| } else { |
| // Rewrite into conjunction. |
| Predicate lower = new BinaryPredicate(BinaryPredicate.Operator.GE, |
| bp.getChild(0), bp.getChild(1)); |
| Predicate upper = new BinaryPredicate(BinaryPredicate.Operator.LE, |
| bp.getChild(0), bp.getChild(2)); |
| result = new CompoundPredicate(CompoundPredicate.Operator.AND, lower, upper); |
| } |
| return result; |
| } |
| |
| private BetweenToCompoundRule() {} |
| } |