org.apache.drill.exec.planner.physical.visitor

Class AdjustOperatorsSchemaVisitor

java.lang.Object

org.apache.drill.exec.planner.physical.visitor.BasePrelVisitor<Prel,Void,RuntimeException>

org.apache.drill.exec.planner.physical.visitor.AdjustOperatorsSchemaVisitor

All Implemented Interfaces:

PrelVisitor<Prel,Void,RuntimeException>

public class AdjustOperatorsSchemaVisitor
extends BasePrelVisitor<Prel,Void,RuntimeException>

AdjustOperatorsSchemaVisitor visits corresponding operators' which depending upon their functionality adjusts their output row types. The adjusting mechanism is unique to each operator. In case of joins this visitor adjusts the field names to make sure that upstream operator only sees that there are unique field names even though the children of the join has same field names. Whereas in case of lateral/unnest operators it changes the correlated field and also the unnest operator's output row type.

Field Summary

Fields inherited from interface org.apache.drill.exec.planner.physical.visitor.PrelVisitor

logger

Constructor Summary

Constructors

Constructor and Description
AdjustOperatorsSchemaVisitor()

Method Summary

Modifier and Type	Method and Description
static Prel	adjustSchema(Prel prel)
void	unRegister()
Prel	visitJoin(JoinPrel prel, Void value)
Prel	visitLateral(LateralJoinPrel prel, Void value)
Prel	visitPrel(Prel prel, Void value)
Prel	visitUnnest(UnnestPrel prel, Void value)

Methods inherited from class org.apache.drill.exec.planner.physical.visitor.BasePrelVisitor

visitExchange, visitLeaf, visitProject, visitScan, visitScan, visitScreen, visitWriter

Methods inherited from class java.lang.Object

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

Constructor Detail

AdjustOperatorsSchemaVisitor

public AdjustOperatorsSchemaVisitor()

Method Detail

adjustSchema

public static Prel adjustSchema(Prel prel)

visitPrel

public Prel visitPrel(Prel prel,
                      Void value)
               throws RuntimeException

Specified by:

visitPrel in interface PrelVisitor<Prel,Void,RuntimeException>

Overrides:

visitPrel in class BasePrelVisitor<Prel,Void,RuntimeException>

Throws:

RuntimeException

unRegister

public void unRegister()

visitJoin

public Prel visitJoin(JoinPrel prel,
                      Void value)
               throws RuntimeException

Specified by:

visitJoin in interface PrelVisitor<Prel,Void,RuntimeException>

Overrides:

visitJoin in class BasePrelVisitor<Prel,Void,RuntimeException>

Throws:

RuntimeException

visitLateral

public Prel visitLateral(LateralJoinPrel prel,
                         Void value)
                  throws RuntimeException

Specified by:

visitLateral in interface PrelVisitor<Prel,Void,RuntimeException>

Overrides:

visitLateral in class BasePrelVisitor<Prel,Void,RuntimeException>

Throws:

RuntimeException

visitUnnest

public Prel visitUnnest(UnnestPrel prel,
                        Void value)
                 throws RuntimeException

Specified by:

visitUnnest in interface PrelVisitor<Prel,Void,RuntimeException>

Overrides:

visitUnnest in class BasePrelVisitor<Prel,Void,RuntimeException>

Throws:

RuntimeException