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

java.lang.Object
  org.apache.hadoop.hive.ql.exec.Operator<MuxDesc>
      org.apache.hadoop.hive.ql.exec.MuxOperator

All Implemented Interfaces:

Serializable, Cloneable, Node

public class MuxOperator
extends Operator<MuxDesc>
implements Serializable

MuxOperator is used in the Reduce side of MapReduce jobs optimized by Correlation Optimizer. Correlation Optimizer will remove unnecessary ReduceSinkOperaotrs, and MuxOperators are used to replace those ReduceSinkOperaotrs. Example: The original operator tree is ... JOIN2 / \ RS4 RS5 / \ GBY1 JOIN1 | / \ RS1 RS2 RS3 If GBY1, JOIN1, and JOIN2 can be executed in the same reducer (optimized by Correlation Optimizer). The new operator tree will be ... JOIN2 | MUX / \ GBY1 JOIN1 \ / DEMUX / | \ / | \ / | \ RS1 RS2 RS3 A MuxOperator has two functions. First, it will construct key, value and tag structure for the input of Join Operators. Second, it is a part of operator coordination mechanism which makes sure the operator tree in the Reducer can work correctly.

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

HIVECOUNTERCREATEDFILES, HIVECOUNTERFATAL

Constructor Summary

MuxOperator()

Method Summary

void	endGroup()
void	forward(Object row, ObjectInspector rowInspector)
String	getName() Implements the getName function for the Node Interface.
static String	getOperatorName()
org.apache.hadoop.hive.ql.plan.api.OperatorType	getType() Return the type of the specific operator among the types in OperatorType.
void	processGroup(int tag)
void	processOp(Object row, int tag) Process the row.
void	startGroup()

Methods inherited from class org.apache.hadoop.hive.ql.exec.Operator

acceptLimitPushdown, augmentPlan, cleanUpInputFileChanged, cleanUpInputFileChangedOp, clone, cloneOp, cloneRecursiveChildren, close, columnNamesRowResolvedCanBeObtained, dump, dump, flush, getChildOperators, getChildren, getColumnExprMap, getConf, getConfiguration, getDone, getExecContext, getGroupKeyObject, getGroupKeyObjectInspector, getIdentifier, getInputObjInspectors, getNumChild, getNumParent, getOperatorId, getOpTraits, getOutputObjInspector, getParentOperators, getSchema, getStatistics, getStats, initialize, initializeLocalWork, initOperatorId, isUseBucketizedHiveInputFormat, jobClose, jobCloseOp, logStats, opAllowedAfterMapJoin, opAllowedBeforeMapJoin, opAllowedBeforeSortMergeJoin, opAllowedConvertMapJoin, passExecContext, preorderMap, removeChild, removeChildAndAdoptItsChildren, removeChildren, removeParent, replaceChild, replaceParent, reset, resetId, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setExecContext, setGroupKeyObject, setGroupKeyObjectInspector, setId, setInputObjInspectors, setOperatorId, setOpTraits, setOutputCollector, setParentOperators, setReporter, setSchema, setStatistics, setUseBucketizedHiveInputFormat, supportAutomaticSortMergeJoin, supportSkewJoinOptimization, supportUnionRemoveOptimization, toString, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

MuxOperator

public MuxOperator()

Method Detail

processOp

public void processOp(Object row,
                      int tag)
               throws HiveException

Description copied from class: Operator

Process the row.

Specified by:

processOp in class Operator<MuxDesc>

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

forward

public void forward(Object row,
                    ObjectInspector rowInspector)
             throws HiveException

Throws:

HiveException

startGroup

public void startGroup()
                throws HiveException

Overrides:

startGroup in class Operator<MuxDesc>

Throws:

HiveException

endGroup

public void endGroup()
              throws HiveException

Overrides:

endGroup in class Operator<MuxDesc>

Throws:

HiveException

processGroup

public void processGroup(int tag)
                  throws HiveException

Overrides:

processGroup in class Operator<MuxDesc>

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<MuxDesc>

Returns:

the name of the operator

getOperatorName

public static String getOperatorName()

getType

public org.apache.hadoop.hive.ql.plan.api.OperatorType getType()

Description copied from class: Operator

Return the type of the specific operator among the types in OperatorType.

Specified by:

getType in class Operator<MuxDesc>

Returns:

OperatorType.*