LimitOptimizer (Eclipse RDF4J 4.2.4)

java.lang.Object
- org.eclipse.rdf4j.query.algebra.helpers.AbstractSimpleQueryModelVisitor<OptimizationException>
- - org.eclipse.rdf4j.federated.optimizer.LimitOptimizer

All Implemented Interfaces:

FedXOptimizer, QueryModelVisitor<OptimizationException>
```
public class LimitOptimizer
extends AbstractSimpleQueryModelVisitor<OptimizationException>
implements FedXOptimizer
```
An optimizer that attempts to push upper limits into BGPs of the query. Currently upper limits are only pushed for simple queries consisting of a single BGP.

Author:

Andreas Schwarte

Constructor Summary

Constructors
Constructor Description

LimitOptimizer()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`meet(Projection proj)`
`void`	`meet(Slice node)`
`void`	`meetOther(QueryModelNode node)`
`void`	`optimize(TupleExpr tupleExpr)`	Optimize the provided tuple expression
`protected void`	`pushLimit(FedXStatementPattern stmt, long upperLimit)`

Methods inherited from class org.eclipse.rdf4j.query.algebra.helpers.AbstractSimpleQueryModelVisitor
meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meet, meetBinaryTupleOperator, meetBinaryValueOperator, meetCompareSubQueryValueOperator, meetNAryValueOperator, meetSubQueryValueOperator, meetUnaryTupleOperator, meetUnaryValueOperator, meetUnsupported, meetUpdateExpr

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

- Constructor Detail
  - LimitOptimizer
```
public LimitOptimizer()
```
- Method Detail
  - optimize
```
public void optimize(TupleExpr tupleExpr)
```
    Description copied from interface: FedXOptimizer
    
    Optimize the provided tuple expression
    
    Specified by:
    
    optimize in interface FedXOptimizer
  - meetOther
```
public void meetOther(QueryModelNode node)
               throws OptimizationException
```
    Specified by:
    
    meetOther in interface QueryModelVisitor<OptimizationException>
    
    Overrides:
    
    meetOther in class AbstractSimpleQueryModelVisitor<OptimizationException>
    
    Throws:
    
    OptimizationException
  - meet
```
public void meet(Slice node)
          throws OptimizationException
```
    Specified by:
    
    meet in interface QueryModelVisitor<OptimizationException>
    
    Overrides:
    
    meet in class AbstractSimpleQueryModelVisitor<OptimizationException>
    
    Throws:
    
    OptimizationException
  - meet
```
public void meet(Projection proj)
          throws OptimizationException
```
    Specified by:
    
    meet in interface QueryModelVisitor<OptimizationException>
    
    Overrides:
    
    meet in class AbstractSimpleQueryModelVisitor<OptimizationException>
    
    Throws:
    
    OptimizationException
  - pushLimit
```
protected void pushLimit(FedXStatementPattern stmt,
                         long upperLimit)
```