org.apache.hadoop.hive.ql.optimizer.physical

Class SparkCrossProductCheck

java.lang.Object

org.apache.hadoop.hive.ql.optimizer.physical.SparkCrossProductCheck

All Implemented Interfaces:

Dispatcher, PhysicalPlanResolver

public class SparkCrossProductCheck
extends Object
implements PhysicalPlanResolver, Dispatcher

Check each MapJoin and ShuffleJoin Operator to see if they are performing a cross product. If yes, output a warning to the Session's console. The Checks made are the following: 1. Shuffle Join: Check the parent ReduceSinkOp of the JoinOp. If its keys list is size = 0, then this is a cross product. 2. Map Join: If the keys expr list on the mapJoin Desc is an empty list for any input, this implies a cross product.

Constructor Summary

Constructors

Constructor and Description
SparkCrossProductCheck()

Method Summary

Methods

Modifier and Type	Method and Description
Object	dispatch(Node nd, Stack<Node> stack, Object... nodeOutputs) Dispatcher function.
PhysicalContext	resolve(PhysicalContext pctx) All physical plan resolvers have to implement this entry method.

Methods inherited from class java.lang.Object

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

Constructor Detail

SparkCrossProductCheck

public SparkCrossProductCheck()

Method Detail

dispatch

public Object dispatch(Node nd,
              Stack<Node> stack,
              Object... nodeOutputs)
                throws SemanticException

Description copied from interface: Dispatcher

Dispatcher function.

Specified by:

dispatch in interface Dispatcher

Parameters:

nd - operator to process.

stack - operator stack to process.

nodeOutputs - The argument list of outputs from processing other nodes that are passed to this dispatcher from the walker.

Returns:

Object The return object from the processing call.

Throws:

SemanticException

resolve

public PhysicalContext resolve(PhysicalContext pctx)
                        throws SemanticException

Description copied from interface: PhysicalPlanResolver

All physical plan resolvers have to implement this entry method.

Specified by:

resolve in interface PhysicalPlanResolver

Returns:

the physical plan

Throws:

SemanticException