content: /*
   *
   *  * Copyright 2020 Alibaba Group Holding Limited.
   *  *
   *  * Licensed 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 com.alibaba.graphscope.common.ir.rel;
  
  import com.alibaba.graphscope.common.ir.rel.type.TargetGraph;
  
  import org.apache.calcite.rel.RelNode;
  
  /**
   * Do operations on graph DB by the input data loading from an external source
   */
  public interface DataSourceOperation {
  
      /**
       * @return external source
       */
      RelNode getExternalSource();
  
      TargetGraph getTargetGraph();
  }
  