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.calcite.plan;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.util.List;
  
  /**
   * Extension to {@link RelOptSchema} with support for sample data-sets.
   *
   * @see RelOptSchema
   */
  public interface RelOptSchemaWithSampling extends RelOptSchema {
    //~ Methods ----------------------------------------------------------------
  
    /**
     * Retrieves a {@link RelOptTable} based upon a member access, using a
     * sample dataset if it exists.
     *
     * @param names       Compound name of table
     * @param datasetName Name of sample dataset to substitute, if it exists;
     *                    null to not look for a sample
     * @param usedDataset Output parameter which is set to true if a sample
     *                    dataset is found; may be null
     * @return Table, or null if not found
     */
    @Nullable RelOptTable getTableForMember(
        List<String> names,
        @Nullable String datasetName,
        boolean @Nullable [] usedDataset);
  }
  