Class FieldValueFeature

  • All Implemented Interfaces:
    Direct Known Subclasses:

    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 if docValues=false

    NumericDocValuesFVFS: used for docValues=true, if docValueType == NUMERIC

    SortedDocValuesFVFS: used for docValues=true, if docValueType == SORTED

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

    Use LegacyFieldValueFeature for the pre 9.4 behaviour of not using DocValues when docValues=true is combined with stored=true.