org.apache.hadoop.hive.ql.exec
Class UnionOperator

java.lang.Object
  extended by org.apache.hadoop.hive.ql.exec.Operator<unionDesc>
      extended by org.apache.hadoop.hive.ql.exec.UnionOperator
All Implemented Interfaces:
Serializable, Node

public class UnionOperator
extends Operator<unionDesc>
implements Serializable

Union Operator Just forwards. Doesn't do anything itself.

See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.exec.Operator
Operator.OperatorFunc, Operator.State
 
Field Summary
 
Fields inherited from class org.apache.hadoop.hive.ql.exec.Operator
alias, childOperators, childOperatorsArray, childOperatorsTag, colExprMap, conf, done, id, inputObjInspectors, LOG, out, outputObjInspector, parentOperators, reporter, state, statsMap
 
Constructor Summary
UnionOperator()
           
 
Method Summary
 String getName()
          Implements the getName function for the Node Interface.
protected  void initializeOp(org.apache.hadoop.conf.Configuration hconf)
          UnionOperator will transform the input rows if the inputObjInspectors from different parents are different.
 void process(Object row, int tag)
          Process the row.
 
Methods inherited from class org.apache.hadoop.hive.ql.exec.Operator
areAllParentsInitialized, close, closeOp, dump, endGroup, forward, getChildOperators, getChildren, getColumnExprMap, getConf, getDone, getIdentifier, getParentOperators, getSchema, getStats, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initializeChildren, jobClose, logStats, preorderMap, removeChild, replaceChild, replaceParent, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setDone, setId, setOutputCollector, setParentOperators, setReporter, setSchema, startGroup
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

UnionOperator

public UnionOperator()
Method Detail

initializeOp

protected void initializeOp(org.apache.hadoop.conf.Configuration hconf)
                     throws HiveException
UnionOperator will transform the input rows if the inputObjInspectors from different parents are different. If one parent has exactly the same ObjectInspector as the output ObjectInspector, then we don't need to do transformation for that parent. This information is recorded in needsTransform[].

Overrides:
initializeOp in class Operator<unionDesc>
Throws:
HiveException

process

public void process(Object row,
                    int tag)
             throws HiveException
Description copied from class: Operator
Process the row.

Specified by:
process in class Operator<unionDesc>
Parameters:
row - The object representing the row.
tag - The tag of the row usually means which parent this row comes from. Rows with the same tag should have exactly the same rowInspector all the time.
Throws:
HiveException

getName

public String getName()
Description copied from class: Operator
Implements the getName function for the Node Interface.

Specified by:
getName in interface Node
Overrides:
getName in class Operator<unionDesc>
Returns:
the name of the operator


Copyright © 2009 The Apache Software Foundation