Package io.trino.sql.planner.iterative.rule

Class PushProjectionThroughExchange

java.lang.Object

io.trino.sql.planner.iterative.rule.PushProjectionThroughExchange

All Implemented Interfaces:

Rule<ProjectNode>

public class PushProjectionThroughExchange
extends Object
implements Rule<ProjectNode>

Transforms:

  Project(x = e1, y = e2)
    Exchange()
      Source(a, b, c)
  

to:

  Exchange()
    Project(x = e1, y = e2)
      Source(a, b, c)
  

Or if Exchange needs symbols from Source for partitioning, ordering or as hash symbol to:

  Project(x, y)
    Exchange()
      Project(x = e1, y = e2, a)
        Source(a, b, c)
  

To avoid looping this optimizer will not be fired if upper Project contains just symbol references.

Nested Class Summary

Nested classes/interfaces inherited from interface io.trino.sql.planner.iterative.Rule

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
PushProjectionThroughExchange()

Method Summary

Modifier and Type	Method	Description
Rule.Result	apply(ProjectNode project, Captures captures, Rule.Context context)
Pattern<ProjectNode>	getPattern()	Returns a pattern to which plan nodes this rule applies.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.trino.sql.planner.iterative.Rule

isEnabled

Constructor Details

PushProjectionThroughExchange

public PushProjectionThroughExchange()

Method Details

getPattern

public Pattern<ProjectNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<ProjectNode>

apply

public Rule.Result apply(ProjectNode project,
 Captures captures,
 Rule.Context context)

Specified by:

apply in interface Rule<ProjectNode>