MergeProjectWithValues (trino-main 366 API)

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 <- a
      d <- b
      e <- f(b)
      f <- 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 <- 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

All Methods Instance Methods Concrete Methods
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 Detail

MergeProjectWithValues

public MergeProjectWithValues(Metadata metadata)

Method Detail

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>