MaterializedViewSubstitutionVisitor.ProjectToProjectUnifyRule1 (Apache Calcite API)

java.lang.Object
- org.apache.calcite.plan.SubstitutionVisitor.UnifyRule
- - org.apache.calcite.plan.SubstitutionVisitor.AbstractUnifyRule
  - - org.apache.calcite.plan.MaterializedViewSubstitutionVisitor.ProjectToProjectUnifyRule1

Enclosing class:

MaterializedViewSubstitutionVisitor
```
private static class MaterializedViewSubstitutionVisitor.ProjectToProjectUnifyRule1
extends SubstitutionVisitor.AbstractUnifyRule
```
Implementation of SubstitutionVisitor.UnifyRule that matches a MutableProject to a MutableProject where the condition of the target relation is weaker.
Example: target has a weaker condition and contains all columns selected by query
- query: Project(projects: [$2, $0]) Filter(condition: >($1, 20)) Scan(table: [hr, emps])
- target: Project(projects: [$0, $1, $2]) Filter(condition: >($1, 10)) Scan(table: [hr, emps])

Field Summary

Fields
Modifier and Type Field Description

static MaterializedViewSubstitutionVisitor.ProjectToProjectUnifyRule1 INSTANCE
- Fields inherited from class org.apache.calcite.plan.SubstitutionVisitor.UnifyRule
  queryOperand, slotCount, targetOperand

Constructor Summary

Constructors
Modifier Constructor Description

private ProjectToProjectUnifyRule1()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected SubstitutionVisitor.UnifyResult`	`apply(SubstitutionVisitor.UnifyRuleCall call)`	Applies this rule to a particular node in a query.
`protected SubstitutionVisitor.UnifyRuleCall`	`match(SubstitutionVisitor visitor, MutableRel query, MutableRel target)`

Methods inherited from class org.apache.calcite.plan.SubstitutionVisitor.AbstractUnifyRule
any, isValid, operand, query, target

Methods inherited from class org.apache.calcite.plan.SubstitutionVisitor.UnifyRule
copy

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - INSTANCE
```
public static final MaterializedViewSubstitutionVisitor.ProjectToProjectUnifyRule1 INSTANCE
```
- Constructor Detail
  - ProjectToProjectUnifyRule1
```
private ProjectToProjectUnifyRule1()
```
- Method Detail
  - apply
```
protected SubstitutionVisitor.UnifyResult apply(SubstitutionVisitor.UnifyRuleCall call)
```
    Description copied from class: SubstitutionVisitor.UnifyRule
    Applies this rule to a particular node in a query. The goal is to convert query into target. Before the rule is invoked, Calcite has made sure that query's children are equivalent to target's children.
    There are 3 possible outcomes:
    
    query already exactly matches target; returns target
    
    query is sufficiently close to a match for target; returns target
    
    query cannot be made to match target; returns null
    
    REVIEW: Is possible that we match query PLUS one or more of its ancestors?
    Specified by:
    
    apply in class SubstitutionVisitor.UnifyRule
    
    Parameters:
    
    call - Input parameters
  - match
```
protected SubstitutionVisitor.UnifyRuleCall match(SubstitutionVisitor visitor,
                                                  MutableRel query,
                                                  MutableRel target)
```
    Overrides:
    
    match in class SubstitutionVisitor.UnifyRule