/**
 * 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.pinot.core.plan;

import org.apache.pinot.core.common.Block;
import org.apache.pinot.core.common.Operator;
import org.apache.pinot.spi.annotations.InterfaceAudience;


/**
 * The <code>PlanNode</code> is a single execution plan node inside the {@link Plan} tree.
 */
@InterfaceAudience.Private
public interface PlanNode {

  /**
   * Get the execution operator associated with the plan node.
   *
   * @return execution operator.
   */
  Operator<? extends Block> run();
}