TransformFilterPlacementConservative (Apache Jena ARQ)

java.lang.Object
- org.apache.jena.sparql.algebra.TransformCopy
- - org.apache.jena.sparql.algebra.optimize.TransformFilterPlacementConservative

All Implemented Interfaces:

Transform
```
public class TransformFilterPlacementConservative
extends TransformCopy
```
Rewrite an algebra expression to put filters as close to their bound variables in a BGP. Works on (filter (BGP ...) )
This is a conservative and relatively limited optimization and has been superseded in the default optimizer by the TransformFilterPlacement as of the 2.11.x releases. This original version of TransformFilterPlacement only operates on filters over BGPs, quad blocks, sequences and conditions (a form of LeftJoin with no scope issues) of the same. However in some cases it may be desirable to have the more limited and conservative behaviour so this is preserved in the code for those who want to use this.

The context flag ARQ.optFilterPlacementConservative may be set to have the default optimizer use this in place of the newer and more aggressive TransformFilterPlacement

- Field Summary
  - Fields inherited from class org.apache.jena.sparql.algebra.TransformCopy
    COPY_ALWAYS, COPY_ONLY_ON_CHANGE
- Constructor Summary
  
  Constructors
  Constructor Description
  
  TransformFilterPlacementConservative()
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  Op transform(OpFilter opFilter, Op x)
  - Methods inherited from class org.apache.jena.sparql.algebra.TransformCopy
    transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform
  - Methods inherited from class java.lang.Object
    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - TransformFilterPlacementConservative
```
public TransformFilterPlacementConservative()
```
- Method Detail
  - transform
```
public Op transform(OpFilter opFilter,
                    Op x)
```
    Specified by:
    
    transform in interface Transform
    
    Overrides:
    
    transform in class TransformCopy