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

Class MergeProjectWithValues

java.lang.Object

io.trino.sql.planner.iterative.rule.MergeProjectWithValues

All Implemented Interfaces:

Rule<ProjectNode>

public class MergeProjectWithValues
extends Object
implements Rule<ProjectNode>

Transforms:

 - Project
      a invalid input: '<'- a
      d invalid input: '<'- b
      e invalid input: '<'- f(b)
      f invalid input: '<'- 1
      - Values(a, b, c)
          expr_a_1, expr_b_1, expr_c_1
          expr_a_2, expr_b_2, expr_c_2
 

into:

 - Values (a, d, e, f)
      expr_a_1, expr_b_1, f(expr_b_1), 1
      expr_a_2, expr_b_2, f(expr_b_2), 1
 

Note: this rule does not fire if ValuesNode contains a non-deterministic expression and it is referenced more than once in ProjectNode's assignments. This is to prevent incorrect results in the following case:

 - project
      row invalid input: '<'- ROW(rand, rand)
      - Values(rand)
          rand()
 

The expected result of the projection is a row with both fields equal. However, if the non-deterministic expression rand() was inlined, we would get two independent random values.

Nested Class Summary

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

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
MergeProjectWithValues(Metadata metadata)

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Details

MergeProjectWithValues

public MergeProjectWithValues(Metadata metadata)

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>

isEnabled

public boolean isEnabled(Session session)

Specified by:

isEnabled in interface Rule<ProjectNode>

apply

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

Specified by:

apply in interface Rule<ProjectNode>