org.apache.hadoop.hive.ql.exec

Class UnionOperator

java.lang.Object

org.apache.hadoop.hive.ql.exec.Operator<UnionDesc>

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

All Implemented Interfaces:

Serializable, Cloneable, 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, CONTEXT_NAME_KEY, done, groupKeyObject, HIVECOUNTERCREATEDFILES, HIVECOUNTERFATAL, id, inputObjInspectors, isLogDebugEnabled, isLogInfoEnabled, isLogTraceEnabled, LOG, operatorId, out, outputObjInspector, parentOperators, PLOG, reporter, state, statsMap

Constructor Summary

Constructors

Constructor and Description
UnionOperator()

Method Summary

Methods

Modifier and Type	Method and Description
String	getName() Implements the getName function for the Node Interface.
static String	getOperatorName()
OperatorType	getType() Return the type of the specific operator among the types in OperatorType.
protected Collection<Future<?>>	initializeOp(org.apache.hadoop.conf.Configuration hconf) UnionOperator will transform the input rows if the inputObjInspectors from different parents are different.
boolean	opAllowedAfterMapJoin()
boolean	opAllowedBeforeMapJoin() Union operators are not allowed either before or after a explicit mapjoin hint.
boolean	opAllowedBeforeSortMergeJoin()
void	process(Object row, int tag) Process the row.

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

acceptLimitPushdown, allInitializedParentsAreClosed, areAllParentsInitialized, augmentPlan, cleanUpInputFileChanged, cleanUpInputFileChangedOp, clone, cloneOp, cloneRecursiveChildren, close, closeOp, columnNamesRowResolvedCanBeObtained, completeInitializationOp, createDummy, defaultEndGroup, defaultStartGroup, dump, dump, endGroup, flush, forward, getAdditionalCounters, getChildOperators, getChildren, getColumnExprMap, getConf, getConfiguration, getDone, getExecContext, getGroupKeyObject, getIdentifier, getInputObjInspectors, getNextCntr, getNumChild, getNumParent, getOperatorId, getOpTraits, getOutputObjInspector, getParentOperators, getSchema, getStatistics, getStats, initEvaluators, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initialize, initializeChildren, initializeLocalWork, initOperatorId, isUseBucketizedHiveInputFormat, jobClose, jobCloseOp, logStats, opAllowedConvertMapJoin, passExecContext, preorderMap, processGroup, removeChild, removeChildAndAdoptItsChildren, removeChildren, removeParent, replaceChild, replaceParent, reset, resetId, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setDone, setExecContext, setGroupKeyObject, setId, setInputContext, setInputObjInspectors, setOperatorId, setOpTraits, setOutputCollector, setParentOperators, setReporter, setSchema, setStatistics, setUseBucketizedHiveInputFormat, startGroup, supportAutomaticSortMergeJoin, supportSkewJoinOptimization, supportUnionRemoveOptimization, toString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

UnionOperator

public UnionOperator()

Method Detail

initializeOp

protected Collection<Future<?>> 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

getOperatorName

public static String getOperatorName()

getType

public 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<UnionDesc>

Returns:

OperatorType.*

opAllowedBeforeMapJoin

public boolean opAllowedBeforeMapJoin()

Union operators are not allowed either before or after a explicit mapjoin hint. Note that, the same query would just work without the mapjoin hint (by setting hive.auto.convert.join to true).

Overrides:

opAllowedBeforeMapJoin in class Operator<UnionDesc>

opAllowedAfterMapJoin

public boolean opAllowedAfterMapJoin()

Overrides:

opAllowedAfterMapJoin in class Operator<UnionDesc>

opAllowedBeforeSortMergeJoin

public boolean opAllowedBeforeSortMergeJoin()

Overrides:

opAllowedBeforeSortMergeJoin in class Operator<UnionDesc>