content: /*
   * 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.beam.sdk.extensions.sql.impl.rel;
  
  import java.util.List;
  import org.apache.beam.sdk.extensions.sql.impl.planner.BeamCostModel;
  import org.apache.beam.sdk.extensions.sql.impl.planner.BeamRelMetadataQuery;
  import org.apache.beam.sdk.extensions.sql.impl.planner.NodeStats;
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionList;
  import org.apache.beam.sdk.values.Row;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.plan.RelOptCluster;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.plan.RelOptPlanner;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.plan.RelTraitSet;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.RelNode;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.core.Intersect;
  import org.apache.beam.vendor.calcite.v1_40_0.org.apache.calcite.rel.core.SetOp;
  
  /**
   * {@code BeamRelNode} to replace a {@code Intersect} node.
   *
   * <p>This is used to combine two SELECT statements, but returns rows only from the first SELECT
   * statement that are identical to a row in the second SELECT statement.
   */
  public class BeamIntersectRel extends Intersect implements BeamRelNode {
    public BeamIntersectRel(
        RelOptCluster cluster, RelTraitSet traits, List<RelNode> inputs, boolean all) {
      super(cluster, traits, inputs, all);
    }
  
    @Override
    public SetOp copy(RelTraitSet traitSet, List<RelNode> inputs, boolean all) {
      return new BeamIntersectRel(getCluster(), traitSet, inputs, all);
    }
  
    @Override
    public PTransform<PCollectionList<Row>, PCollection<Row>> buildPTransform() {
      return new BeamSetOperatorRelBase(this, BeamSetOperatorRelBase.OpType.INTERSECT, all);
    }
  
    @Override
    public NodeStats estimateNodeStats(BeamRelMetadataQuery mq) {
      // This takes the minimum of the inputs for all the estimate factors.
      double minimumRows = Double.POSITIVE_INFINITY;
      double minimumWindowSize = Double.POSITIVE_INFINITY;
      double minimumRate = Double.POSITIVE_INFINITY;
  
      for (RelNode input : inputs) {
        NodeStats inputEstimates = BeamSqlRelUtils.getNodeStats(input, mq);
        minimumRows = Math.min(minimumRows, inputEstimates.getRowCount());
        minimumRate = Math.min(minimumRate, inputEstimates.getRate());
        minimumWindowSize = Math.min(minimumWindowSize, inputEstimates.getWindow());
      }
  
      return NodeStats.create(minimumRows, minimumRate, minimumWindowSize).multiply(0.5);
    }
  
    @Override
    public BeamCostModel beamComputeSelfCost(RelOptPlanner planner, BeamRelMetadataQuery mq) {
  
      NodeStats inputsStatSummation =
          inputs.stream()
              .map(input -> BeamSqlRelUtils.getNodeStats(input, mq))
              .reduce(NodeStats.create(0, 0, 0), NodeStats::plus);
  
      return BeamCostModel.FACTORY.makeCost(
          inputsStatSummation.getRowCount(), inputsStatSummation.getRate());
    }
  }
  