IntersectToDistinctRule (Apache Calcite API)

java.lang.Object
- org.apache.calcite.plan.RelOptRule
- - org.apache.calcite.rel.rules.IntersectToDistinctRule

```
public class IntersectToDistinctRule
extends RelOptRule
```
Planner rule that translates a distinct Intersect (all = false) into a group of operators composed of Union, Aggregate, etc.
Rewrite: (GB-Union All-GB)-GB-UDTF (on all attributes)
Example

Query: R1 Intersect All R2
R3 = GB(R1 on all attributes, count(*) as c) union all GB(R2 on all attributes, count(*) as c)
R4 = GB(R3 on all attributes, count(c) as cnt, min(c) as m)
Note that we do not need min(c) in intersect distinct.
R5 = Filter(cnt == #branch)
If it is intersect all then
R6 = UDTF (R5) which will explode the tuples based on min(c) R7 = Project(R6 on all attributes)
Else
R6 = Proj(R5 on all attributes)

See Also:

UnionToDistinctRule

Field Summary

Fields
Modifier and Type Field Description

static IntersectToDistinctRule INSTANCE
- Fields inherited from class org.apache.calcite.plan.RelOptRule
  description, operands, relBuilderFactory

Constructor Summary

Constructors
Constructor	Description
`IntersectToDistinctRule(java.lang.Class<? extends Intersect> intersectClazz, RelBuilderFactory relBuilderFactory)`	Creates an IntersectToDistinctRule.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

void onMatch(RelOptRuleCall call)
Receives notification about a rule match.
- Methods inherited from class org.apache.calcite.plan.RelOptRule
  any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered
- Methods inherited from class java.lang.Object
  clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - INSTANCE
```
public static final IntersectToDistinctRule INSTANCE
```
- Constructor Detail
  - IntersectToDistinctRule
```
public IntersectToDistinctRule(java.lang.Class<? extends Intersect> intersectClazz,
                               RelBuilderFactory relBuilderFactory)
```
    Creates an IntersectToDistinctRule.
- Method Detail
  - onMatch
```
public void onMatch(RelOptRuleCall call)
```
    Description copied from class: RelOptRule
    
    Receives notification about a rule match. At the time that this method is called, call.rels holds the set of relational expressions which match the operands to the rule; call.rels[0] is the root expression.
    Typically a rule would check that the nodes are valid matches, creates a new expression, then calls back RelOptRuleCall.transformTo(org.apache.calcite.rel.RelNode, java.util.Map<org.apache.calcite.rel.RelNode, org.apache.calcite.rel.RelNode>) to register the expression.
    
    Specified by:
    
    onMatch in class RelOptRule
    
    Parameters:
    
    call - Rule call
    
    See Also:
    
    RelOptRule.matches(RelOptRuleCall)