org.apache.solr.ltr.feature

Class FieldValueFeature

java.lang.Object

org.apache.lucene.search.Query

org.apache.solr.ltr.feature.Feature

org.apache.solr.ltr.feature.FieldValueFeature

All Implemented Interfaces:

Accountable

public class FieldValueFeature
extends Feature

This feature returns the value of a field in the current document. The field must have stored="true" or docValues="true" properties. Example configuration:

{
  "name":  "rawHits",
  "class": "org.apache.solr.ltr.feature.FieldValueFeature",
  "params": {
      "field": "hits"
  }
}

There are 4 different types of FeatureScorers that a FieldValueFeatureWeight may use. The chosen scorer depends on the field attributes.

FieldValueFeatureScorer (FVFS): used for stored=true, no matter if docValues=true or docValues=false

NumericDocValuesFVFS: used for stored=false and docValues=true, if docValueType == NUMERIC

SortedDocValuesFVFS: used for stored=false and docValues=true, if docValueType == SORTED

DefaultValueFVFS: used for stored=false and docValues=true, a fallback scorer that is used on segments where no document has a value set in the field of this feature

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	FieldValueFeature.FieldValueFeatureWeight

Nested classes/interfaces inherited from class org.apache.solr.ltr.feature.Feature

Feature.FeatureWeight

Field Summary

Fields inherited from class org.apache.solr.ltr.feature.Feature

name

Fields inherited from interface org.apache.lucene.util.Accountable

NULL_ACCOUNTABLE

Constructor Summary

Constructors

Constructor and Description
FieldValueFeature(String name, Map<String,Object> params)

Method Summary

Modifier and Type	Method and Description
Feature.FeatureWeight	createWeight(IndexSearcher searcher, boolean needsScores, SolrQueryRequest request, Query originalQuery, Map<String,String[]> efi)
String	getField()
LinkedHashMap<String,Object>	paramsToMap()
void	setField(String field)
protected void	validate() As part of creation of a feature instance, this function confirms that the feature parameters are valid.

Methods inherited from class org.apache.solr.ltr.feature.Feature

defaultParamsToMap, equals, getDefaultValue, getIndex, getInstance, getName, hashCode, ramBytesUsed, setDefaultValue, setIndex, toString, visit

Methods inherited from class org.apache.lucene.search.Query

classHash, createWeight, rewrite, sameClassAs, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.lucene.util.Accountable

getChildResources

Constructor Detail

FieldValueFeature

public FieldValueFeature(String name,
                         Map<String,Object> params)

Method Detail

getField

public String getField()

setField

public void setField(String field)

paramsToMap

public LinkedHashMap<String,Object> paramsToMap()

Specified by:

paramsToMap in class Feature

validate

protected void validate()
                 throws FeatureException

Description copied from class: Feature

As part of creation of a feature instance, this function confirms that the feature parameters are valid.

Specified by:

validate in class Feature

Throws:

FeatureException - Feature Exception

createWeight

public Feature.FeatureWeight createWeight(IndexSearcher searcher,
                                          boolean needsScores,
                                          SolrQueryRequest request,
                                          Query originalQuery,
                                          Map<String,String[]> efi)
                                   throws IOException

Specified by:

createWeight in class Feature

Throws:

IOException