org.apache.hadoop.hive.ql.optimizer.topnkey

Class TopNKeyProcessor

java.lang.Object

org.apache.hadoop.hive.ql.optimizer.topnkey.TopNKeyProcessor

All Implemented Interfaces:

NodeProcessor, SemanticNodeProcessor

public class TopNKeyProcessor
extends Object
implements SemanticNodeProcessor

TopNKeyProcessor is a processor for TopNKeyOperator. A TopNKeyOperator will be placed before any ReduceSinkOperator which has a topN property >= 0.

Constructor Summary

Constructors

Constructor and Description
TopNKeyProcessor()
TopNKeyProcessor(int maxTopNAllowed, float efficiencyThreshold, long checkEfficiencyNumBatches, int maxNumberOfPartitions)

Method Summary

Modifier and Type	Method and Description
static Operator<? extends OperatorDesc>	copyDown(Operator<? extends OperatorDesc> child, OperatorDesc operatorDesc)
Object	process(Node nd, Stack<Node> stack, NodeProcessorCtx procCtx, Object... nodeOutputs) Generic process for all ops that don't have specific implementations.

Methods inherited from class java.lang.Object

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

Constructor Detail

TopNKeyProcessor

public TopNKeyProcessor()

TopNKeyProcessor

public TopNKeyProcessor(int maxTopNAllowed,
                        float efficiencyThreshold,
                        long checkEfficiencyNumBatches,
                        int maxNumberOfPartitions)

Method Detail

process

public Object process(Node nd,
                      Stack<Node> stack,
                      NodeProcessorCtx procCtx,
                      Object... nodeOutputs)
               throws SemanticException

Description copied from interface: SemanticNodeProcessor

Generic process for all ops that don't have specific implementations.

Specified by:

process in interface NodeProcessor

Specified by:

process in interface SemanticNodeProcessor

Parameters:

nd - operator to process

procCtx - operator processor context

nodeOutputs - A variable argument list of outputs from other nodes in the walk

Returns:

Object to be returned by the process call

Throws:

SemanticException

copyDown

public static Operator<? extends OperatorDesc> copyDown(Operator<? extends OperatorDesc> child,
                                                        OperatorDesc operatorDesc)