SubstitutionVisitor.ScanToProjectUnifyRule (Apache Calcite API)

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

Enclosing class:: SubstitutionVisitor

private static class SubstitutionVisitor.ScanToProjectUnifyRule
extends SubstitutionVisitor.AbstractUnifyRule

Implementation of SubstitutionVisitor.UnifyRule that matches LogicalTableScan.

Field Summary

Fields
Modifier and Type Field Description

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

Constructor Summary

Constructors
Modifier Constructor Description

private ScanToProjectUnifyRule()

Method Summary

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

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, match

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

- Field Detail
  - INSTANCE
```
public static final SubstitutionVisitor.ScanToProjectUnifyRule INSTANCE
```
- Constructor Detail
  - ScanToProjectUnifyRule
```
private ScanToProjectUnifyRule()
```
- Method Detail
  - apply
```
public 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