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

Class PrelVisualizerVisitor

java.lang.Object

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

All Implemented Interfaces:

PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

public class PrelVisualizerVisitor
extends Object
implements PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Debug-time class that prints a PRel tree to the console for inspection. Insert this into code during development to see the state of the tree at various points of interest during the planning process.

Use this by inserting lines into our prel transforms to see what is happening. This is useful if you must understand the transforms, or change them. For example:

In file: DefaultSqlHandler#convertToPrel():

 PrelVisualizerVisitor.print("Before EER", phyRelNode); // Debug only
 phyRelNode = ExcessiveExchangeIdentifier.removeExcessiveEchanges(phyRelNode, targetSliceSize);
 PrelVisualizerVisitor.print("After EER", phyRelNode); // Debug only
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PrelVisualizerVisitor.VisualizationState

Field Summary

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

logger

Constructor Summary

Constructors

Constructor and Description
PrelVisualizerVisitor()

Method Summary

Methods

Modifier and Type	Method and Description
static void	print(String label, Prel prel)
Void	visitExchange(ExchangePrel prel, PrelVisualizerVisitor.VisualizationState value)
Void	visitJoin(JoinPrel prel, PrelVisualizerVisitor.VisualizationState value)
Void	visitPrel(Prel prel, PrelVisualizerVisitor.VisualizationState value)
Void	visitProject(ProjectPrel prel, PrelVisualizerVisitor.VisualizationState value)
Void	visitScan(ScanPrel prel, PrelVisualizerVisitor.VisualizationState value)
Void	visitScreen(ScreenPrel prel, PrelVisualizerVisitor.VisualizationState value)
Void	visitWriter(WriterPrel prel, PrelVisualizerVisitor.VisualizationState value)
static String	visualize(Prel prel)

Methods inherited from class java.lang.Object

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

Constructor Detail

PrelVisualizerVisitor

public PrelVisualizerVisitor()

Method Detail

print

public static void print(String label,
         Prel prel)

visualize

public static String visualize(Prel prel)

visitExchange

public Void visitExchange(ExchangePrel prel,
                 PrelVisualizerVisitor.VisualizationState value)
                   throws Exception

Specified by:

visitExchange in interface PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Throws:

Exception

visitScreen

public Void visitScreen(ScreenPrel prel,
               PrelVisualizerVisitor.VisualizationState value)
                 throws Exception

Specified by:

visitScreen in interface PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Throws:

Exception

visitWriter

public Void visitWriter(WriterPrel prel,
               PrelVisualizerVisitor.VisualizationState value)
                 throws Exception

Specified by:

visitWriter in interface PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Throws:

Exception

visitScan

public Void visitScan(ScanPrel prel,
             PrelVisualizerVisitor.VisualizationState value)
               throws Exception

Specified by:

visitScan in interface PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Throws:

Exception

visitJoin

public Void visitJoin(JoinPrel prel,
             PrelVisualizerVisitor.VisualizationState value)
               throws Exception

Specified by:

visitJoin in interface PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Throws:

Exception

visitProject

public Void visitProject(ProjectPrel prel,
                PrelVisualizerVisitor.VisualizationState value)
                  throws Exception

Specified by:

visitProject in interface PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Throws:

Exception

visitPrel

public Void visitPrel(Prel prel,
             PrelVisualizerVisitor.VisualizationState value)
               throws Exception

Specified by:

visitPrel in interface PrelVisitor<Void,PrelVisualizerVisitor.VisualizationState,Exception>

Throws:

Exception