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

static MemoryMXBean

memoryMXBean

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

HIVECOUNTERCREATEDFILES, HIVECOUNTERFATAL

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.
List<String>	genColLists(HashMap<Operator<? extends OperatorDesc>,OpParseContext> opParseCtx)
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.
static javolution.util.FastBitSet	groupingSet2BitSet(int value)
void	processOp(Object row, int tag) Process the row.
void	startGroup()

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

augmentPlan, cleanUpInputFileChanged, cleanUpInputFileChangedOp, clone, cloneOp, cloneRecursiveChildren, close, columnNamesRowResolvedCanBeObtained, dump, dump, 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, processGroup, 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

Field Detail

memoryMXBean

public static MemoryMXBean memoryMXBean

Constructor Detail

GroupByOperator

public GroupByOperator()

Method Detail

groupingSet2BitSet

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

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

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.

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 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<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>