| /* |
| * 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.calcite.rel; |
| |
| import org.apache.calcite.plan.RelMultipleTrait; |
| |
| import java.util.List; |
| |
| /** |
| * Description of the physical ordering of a relational expression. |
| * |
| * <p>An ordering consists of a list of one or more column ordinals and the |
| * direction of the ordering. |
| */ |
| public interface RelCollation extends RelMultipleTrait { |
| //~ Methods ---------------------------------------------------------------- |
| |
| /** |
| * Returns the ordinals and directions of the columns in this ordering. |
| */ |
| List<RelFieldCollation> getFieldCollations(); |
| } |
| |
| // End RelCollation.java |