thomasrebele commented on a change in pull request #2109: URL: https://github.com/apache/calcite/pull/2109#discussion_r472135224
########## File path: core/src/main/java/org/apache/calcite/adapter/enumerable/EnumerableLimitSort.java ########## @@ -0,0 +1,146 @@ +/* + * 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.adapter.enumerable; + +import org.apache.calcite.linq4j.tree.BlockBuilder; +import org.apache.calcite.linq4j.tree.Expression; +import org.apache.calcite.linq4j.tree.Expressions; +import org.apache.calcite.plan.RelOptCluster; +import org.apache.calcite.plan.RelOptCost; +import org.apache.calcite.plan.RelOptPlanner; +import org.apache.calcite.plan.RelTraitSet; +import org.apache.calcite.rel.RelCollation; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Sort; +import org.apache.calcite.rel.metadata.RelMetadataQuery; +import org.apache.calcite.rex.RexLiteral; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.util.BuiltInMethod; +import org.apache.calcite.util.Pair; + +import static org.apache.calcite.adapter.enumerable.EnumerableLimit.getExpression; + +/** + * Implementation of {@link org.apache.calcite.rel.core.Sort} in + * {@link org.apache.calcite.adapter.enumerable.EnumerableConvention enumerable calling convention}. + * It optimizes sorts that have a limit and an optional offset. + */ +public class EnumerableLimitSort extends Sort implements EnumerableRel { Review comment: For the same reason that EnumerableSort extends Sort. I guess it is because both classes provide an implementation of a Sort algorithm. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
