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

java.lang.Object
  org.apache.hadoop.hive.ql.exec.Operator<GroupByDesc>
      org.apache.hadoop.hive.ql.exec.GroupByOperator

All Implemented Interfaces:

Serializable, Cloneable, Node

Direct Known Subclasses:

VectorGroupByOperator

public class GroupByOperator
extends Operator<GroupByDesc>
implements Serializable

GroupBy 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.State

Field Summary

protected boolean[]	aggregationIsDistinct
protected ExprNodeEvaluator[][]	aggregationParameterFields
protected ObjectInspector[][]	aggregationParameterObjectInspectors
protected Object[][]	aggregationParameterObjects
protected ObjectInspector[][]	aggregationParameterStandardObjectInspectors
protected GenericUDAFEvaluator.AggregationBuffer[]	aggregations
protected Object[][]	aggregationsParametersLastInvoke
protected ObjectInspector[]	currentKeyObjectInspectors
protected KeyWrapper	currentKeys
protected Map<Integer,Set<Integer>>	distinctKeyAggrs
protected boolean	hashAggr
protected HashMap<KeyWrapper,GenericUDAFEvaluator.AggregationBuffer[]>	hashAggregations
protected ExprNodeEvaluator[]	keyFields
protected ObjectInspector[]	keyObjectInspectors
protected HashSet<KeyWrapper>	keysCurrentGroup
protected long	maxHashTblMemory Max memory usable by the hashtable before it should flush.
protected long	maxMemory Total amount of memory allowed for JVM heap.
static MemoryMXBean	memoryMXBean
protected float	memoryThreshold configure percent of memory threshold usable by QP.
protected KeyWrapper	newKeys
protected List<Integer>	nonDistinctAggrs
protected Map<Integer,Set<Integer>>	nonDistinctKeyAggrs
protected int	numEntriesHashTable Current number of entries in the hash table.
protected ArrayList<ObjectInspector>	objectInspectors

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

alias, childOperators, childOperatorsArray, childOperatorsTag, colExprMap, conf, done, groupKeyObject, groupKeyOI, HIVECOUNTERCREATEDFILES, HIVECOUNTERFATAL, id, inputObjInspectors, isLogInfoEnabled, operatorId, out, outputObjInspector, parentOperators, reporter, state, statsMap

Constructor Summary

GroupByOperator()

Method Summary

boolean	acceptLimitPushdown() we can push the limit above GBY (running in Reducer), since that will generate single row for each group.
void	closeOp(boolean abort) We need to forward all the aggregations to children.
void	endGroup()
void	flush() Forward all aggregations to children.
protected void	forward(Object[] keys, GenericUDAFEvaluator.AggregationBuffer[] aggs) Forward a record of keys and aggregation results.
List<String>	genColLists(HashMap<Operator<? extends OperatorDesc>,OpParseContext> opParseCtx)
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.
static javolution.util.FastBitSet	groupingSet2BitSet(int value)
protected void	initializeOp(org.apache.hadoop.conf.Configuration hconf) Operator specific initialization.
protected GenericUDAFEvaluator.AggregationBuffer[]	newAggregations()
void	processOp(Object row, int tag) Process the row.
protected void	resetAggregations(GenericUDAFEvaluator.AggregationBuffer[] aggs)
void	startGroup()
protected void	updateAggregations(GenericUDAFEvaluator.AggregationBuffer[] aggs, Object row, ObjectInspector rowInspector, boolean hashAggr, boolean newEntryForHashAggr, Object[][] lastInvoke)

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

allInitializedParentsAreClosed, areAllParentsInitialized, augmentPlan, cleanUpInputFileChanged, cleanUpInputFileChangedOp, clone, cloneOp, cloneRecursiveChildren, close, columnNamesRowResolvedCanBeObtained, defaultEndGroup, defaultStartGroup, dump, dump, forward, getAdditionalCounters, getChildOperators, getChildren, getColumnExprMap, getConf, getConfiguration, getDone, getExecContext, getGroupKeyObject, getGroupKeyObjectInspector, getIdentifier, getInputObjInspectors, getNextCntr, getNumChild, getNumParent, getOperatorId, getOpTraits, getOutputObjInspector, getParentOperators, getSchema, getStatistics, getStats, initEvaluators, initEvaluators, initEvaluatorsAndReturnStruct, initialize, initialize, initializeChildren, initializeLocalWork, initOperatorId, isUseBucketizedHiveInputFormat, jobClose, jobCloseOp, logStats, opAllowedAfterMapJoin, opAllowedBeforeMapJoin, opAllowedBeforeSortMergeJoin, opAllowedConvertMapJoin, passExecContext, preorderMap, processGroup, removeChild, removeChildAndAdoptItsChildren, removeChildren, removeParent, replaceChild, replaceParent, reset, resetId, resetStats, setAlias, setChildOperators, setColumnExprMap, setConf, setDone, 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, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

keyFields

protected transient ExprNodeEvaluator[] keyFields

keyObjectInspectors

protected transient ObjectInspector[] keyObjectInspectors

aggregationParameterFields

protected transient ExprNodeEvaluator[][] aggregationParameterFields

aggregationParameterObjectInspectors

protected transient ObjectInspector[][] aggregationParameterObjectInspectors

aggregationParameterStandardObjectInspectors

protected transient ObjectInspector[][] aggregationParameterStandardObjectInspectors

aggregationParameterObjects

protected transient Object[][] aggregationParameterObjects

aggregationIsDistinct

protected transient boolean[] aggregationIsDistinct

distinctKeyAggrs

protected transient Map<Integer,Set<Integer>> distinctKeyAggrs

nonDistinctKeyAggrs

protected transient Map<Integer,Set<Integer>> nonDistinctKeyAggrs

nonDistinctAggrs

protected transient List<Integer> nonDistinctAggrs

objectInspectors

protected transient ArrayList<ObjectInspector> objectInspectors

currentKeys

protected transient KeyWrapper currentKeys

newKeys

protected transient KeyWrapper newKeys

aggregations

protected transient GenericUDAFEvaluator.AggregationBuffer[] aggregations

aggregationsParametersLastInvoke

protected transient Object[][] aggregationsParametersLastInvoke

hashAggregations

protected transient HashMap<KeyWrapper,GenericUDAFEvaluator.AggregationBuffer[]> hashAggregations

keysCurrentGroup

protected transient HashSet<KeyWrapper> keysCurrentGroup

hashAggr

protected transient boolean hashAggr

currentKeyObjectInspectors

protected transient ObjectInspector[] currentKeyObjectInspectors

memoryMXBean

public static MemoryMXBean memoryMXBean

maxMemory

protected long maxMemory

Total amount of memory allowed for JVM heap.

memoryThreshold

protected float memoryThreshold

configure percent of memory threshold usable by QP.

maxHashTblMemory

protected transient long maxHashTblMemory

Max memory usable by the hashtable before it should flush.

numEntriesHashTable

protected transient int numEntriesHashTable

Current number of entries in the hash table.

Constructor Detail

GroupByOperator

public GroupByOperator()

Method Detail

groupingSet2BitSet

public static javolution.util.FastBitSet groupingSet2BitSet(int value)

initializeOp

protected void initializeOp(org.apache.hadoop.conf.Configuration hconf)
                     throws HiveException

Description copied from class: Operator

Operator specific initialization.

Overrides:

initializeOp in class Operator<GroupByDesc>

Throws:

HiveException

newAggregations

protected GenericUDAFEvaluator.AggregationBuffer[] newAggregations()
                                                            throws HiveException

Throws:

HiveException

resetAggregations

protected void resetAggregations(GenericUDAFEvaluator.AggregationBuffer[] aggs)
                          throws HiveException

Throws:

HiveException

updateAggregations

protected void updateAggregations(GenericUDAFEvaluator.AggregationBuffer[] aggs,
                                  Object row,
                                  ObjectInspector rowInspector,
                                  boolean hashAggr,
                                  boolean newEntryForHashAggr,
                                  Object[][] lastInvoke)
                           throws HiveException

Throws:

HiveException

startGroup

public void startGroup()
                throws HiveException

Overrides:

startGroup in class Operator<GroupByDesc>

Throws:

HiveException

endGroup

public void endGroup()
              throws HiveException

Overrides:

endGroup in class Operator<GroupByDesc>

Throws:

HiveException

processOp

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

Description copied from class: Operator

Process the row.

Specified by:

processOp in class Operator<GroupByDesc>

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

protected void forward(Object[] keys,
                       GenericUDAFEvaluator.AggregationBuffer[] aggs)
                throws HiveException

Forward a record of keys and aggregation results.

Parameters:

keys - The keys in the record

Throws:

HiveException

flush

public void flush()
           throws HiveException

Forward all aggregations to children. It is only used by DemuxOperator.

Overrides:

flush in class Operator<GroupByDesc>

Throws:

HiveException

closeOp

public void closeOp(boolean abort)
             throws HiveException

We need to forward all the aggregations to children.

Overrides:

closeOp in class Operator<GroupByDesc>

Throws:

HiveException

genColLists

public List<String> genColLists(HashMap<Operator<? extends OperatorDesc>,OpParseContext> opParseCtx)

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<GroupByDesc>

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<GroupByDesc>

Returns:

OperatorType.*

acceptLimitPushdown

public boolean acceptLimitPushdown()

we can push the limit above GBY (running in Reducer), since that will generate single row for each group. This doesn't necessarily hold for GBY (running in Mappers), so we don't push limit above it.

Overrides:

acceptLimitPushdown in class Operator<GroupByDesc>