/**
* 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.tajo.plan.logical;
import org.apache.tajo.catalog.Schema;
import org.apache.tajo.plan.Target;
import java.util.List;
/**
* Projectable is an interface for a LogicalNode which has a list of targets.
* What a logical node has a list of targets means that the node evaluated a list of expressions.
* For example, {@link ScanNode},
* {@link JoinNode},
* {@link GroupbyNode}, and
* {@link ProjectionNode} are all <i>Projectable</i> nodes.
* The expression evaluation occurs only at those projectable nodes.
*/
public interface Projectable {
/**
* Get a PlanNode Id
* @return PlanNodeId
*/
int getPID();
/**
* check if this node has a target list
* @return TRUE if this node has a target list. Otherwise, FALSE.
*/
boolean hasTargets();
/**
* Set a target list
*
* @param targets The array of targets
*/
void setTargets(List<Target> targets);
/**
* Get a list of targets
*
* @return The array of targets
*/
List<Target> getTargets();
/**
* Get an input schema
* @return The input schema
*/
public Schema getInSchema();
/**
* Get an output schema
*
* @return The output schema
*/
public Schema getOutSchema();
}