| /* |
| * 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.drill.exec.planner.cost; |
| |
| import org.apache.calcite.rel.core.Aggregate; |
| import org.apache.calcite.rel.metadata.BuiltInMetadata; |
| import org.apache.calcite.rel.metadata.ReflectiveRelMetadataProvider; |
| import org.apache.calcite.rel.metadata.RelMdMaxRowCount; |
| import org.apache.calcite.rel.metadata.RelMetadataProvider; |
| import org.apache.calcite.rel.metadata.RelMetadataQuery; |
| |
| public class DrillRelMdMaxRowCount extends RelMdMaxRowCount { |
| |
| public static final RelMetadataProvider SOURCE = |
| ReflectiveRelMetadataProvider.reflectiveSource( |
| new DrillRelMdMaxRowCount(), BuiltInMetadata.MaxRowCount.Handler.class); |
| |
| // The method is overriden because of changes done in CALCITE-2991 and |
| // TODO: should be discarded when CALCITE-1048 is fixed. |
| @Override |
| public Double getMaxRowCount(Aggregate rel, RelMetadataQuery mq) { |
| if (rel.getGroupSet().isEmpty()) { |
| // Aggregate with no GROUP BY always returns 1 row (even on empty table). |
| return 1D; |
| } |
| final Double rowCount = mq.getMaxRowCount(rel.getInput()); |
| if (rowCount == null) { |
| return null; |
| } |
| return rowCount * rel.getGroupSets().size(); |
| } |
| } |