org.apache.hadoop.hive.ql.exec

Class SelectOperator

java.lang.Object

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

org.apache.hadoop.hive.ql.exec.SelectOperator

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Node

public class SelectOperator
extends Operator<SelectDesc>
implements java.io.Serializable

Select operator implementation.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hive.ql.exec.Operator

Operator.OperatorFunc, Operator.ProgressCounter, Operator.State

Field Summary

Fields

Modifier and Type	Field and Description
protected ExprNodeEvaluator[]	eval

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

alias, beginTime, childOperators, childOperatorsArray, childOperatorsTag, colExprMap, conf, counterNames, counterNameToEnum, counters, done, fatalErrorCntr, groupKeyObject, id, inputObjInspectors, inputRows, isLogInfoEnabled, LOG, numInputRowsCntr, numOutputRowsCntr, operatorId, out, outputObjInspector, outputRows, parentOperators, reporter, state, statsMap, timeTakenCntr, totalTime

Constructor Summary

Constructors

Constructor and Description
SelectOperator()

Method Summary

Modifier and Type	Method and Description
boolean	acceptLimitPushdown() used for LimitPushdownOptimizer if all of the operators between limit and reduce-sink does not remove any input rows in the range of limit count, limit can be pushed down to reduce-sink operator.
boolean	columnNamesRowResolvedCanBeObtained()
java.lang.String	getName() Implements the getName function for the Node Interface.
static java.lang.String	getOperatorName()
OperatorType	getType() Return the type of the specific operator among the types in OperatorType.
protected void	initializeOp(Configuration hconf) Operator specific initialization.
void	processOp(java.lang.Object row, int tag) Process the row.
boolean	supportAutomaticSortMergeJoin() Whether this operator supports automatic sort merge join.
boolean	supportSkewJoinOptimization()
boolean	supportUnionRemoveOptimization()

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

allInitializedParentsAreClosed, areAllParentsInitialized, assignCounterNameToEnum, augmentPlan, checkFatalErrors, cleanUpInputFileChanged, cleanUpInputFileChangedOp, clone, close, closeOp, dump, dump, endGroup, fatalErrorMessage, flush, forward, getAdditionalCounters, getChildOperators, getChildren, getColumnExprMap, getConf, getConfiguration, getCounterNames, getCounterNameToEnum, getCounters, getDone, getExecContext, getGroupKeyObject, getIdentifier, getInputObjInspectors, getNextCntr, getNumChild, getNumParent, getOperatorId, getParentOperators, getSchema, getStats, getWrappedCounterName, incrCounter, initEvaluators, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initialize, initializeChildren, initializeCounters, initializeLocalWork, initOperatorId, isUseBucketizedHiveInputFormat, jobClose, jobCloseOp, logStats, opAllowedAfterMapJoin, opAllowedBeforeMapJoin, opAllowedBeforeSortMergeJoin, opAllowedConvertMapJoin, passExecContext, preorderMap, process, processGroup, removeChild, removeChildAndAdoptItsChildren, removeChildren, removeParent, replaceChild, replaceParent, reset, resetId, resetLastEnumUsed, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setCounterNames, setCounterNameToEnum, setDone, setExecContext, setGroupKeyObject, setId, setInputObjInspectors, setOperatorId, setOutputCollector, setParentOperators, setReporter, setSchema, setUseBucketizedHiveInputFormat, startGroup, toString, toString, updateCounters

Methods inherited from class java.lang.Object

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

Field Detail

eval

protected transient ExprNodeEvaluator[] eval

Constructor Detail

SelectOperator

public SelectOperator()

Method Detail

initializeOp

protected void initializeOp(Configuration hconf)
                     throws HiveException

Description copied from class: Operator

Operator specific initialization.

Overrides:

initializeOp in class Operator<SelectDesc>

Throws:

HiveException

processOp

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

Description copied from class: Operator

Process the row.

Specified by:

processOp in class Operator<SelectDesc>

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 java.lang.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<SelectDesc>

Returns:

the name of the operator

getOperatorName

public static java.lang.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<SelectDesc>

Returns:

OperatorType.*

supportSkewJoinOptimization

public boolean supportSkewJoinOptimization()

Overrides:

supportSkewJoinOptimization in class Operator<SelectDesc>

columnNamesRowResolvedCanBeObtained

public boolean columnNamesRowResolvedCanBeObtained()

Overrides:

columnNamesRowResolvedCanBeObtained in class Operator<SelectDesc>

supportAutomaticSortMergeJoin

public boolean supportAutomaticSortMergeJoin()

Description copied from class: Operator

Whether this operator supports automatic sort merge join. The stack is traversed, and this method is invoked for all the operators.

Overrides:

supportAutomaticSortMergeJoin in class Operator<SelectDesc>

Returns:

TRUE if yes, FALSE otherwise.

supportUnionRemoveOptimization

public boolean supportUnionRemoveOptimization()

Overrides:

supportUnionRemoveOptimization in class Operator<SelectDesc>

acceptLimitPushdown

public boolean acceptLimitPushdown()

Description copied from class: Operator

used for LimitPushdownOptimizer if all of the operators between limit and reduce-sink does not remove any input rows in the range of limit count, limit can be pushed down to reduce-sink operator. forward, select, etc.

Overrides:

acceptLimitPushdown in class Operator<SelectDesc>