processing/src/main/java/org/apache/druid/query/search/RoaringBitmapDecisionHelper.java

/*
 * 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.druid.query.search;

public class RoaringBitmapDecisionHelper extends SearchQueryDecisionHelper
{
  // This value comes from an experiment.
  // See the discussion at https://github.com/apache/druid/pull/3792#issuecomment-268331804.
  private static final double BITMAP_INTERSECT_COST = 4.5;
  private static final RoaringBitmapDecisionHelper INSTANCE = new RoaringBitmapDecisionHelper();

  public static RoaringBitmapDecisionHelper instance()
  {
    return INSTANCE;
  }

  private RoaringBitmapDecisionHelper()
  {
    super(BITMAP_INTERSECT_COST);
  }
}