Rank feature datatype
editRank feature datatype
editA rank_feature
field can index numbers so that they can later be used to boost
documents in queries with a rank_feature
query.
PUT my_index { "mappings": { "properties": { "pagerank": { "type": "rank_feature" }, "url_length": { "type": "rank_feature", "positive_score_impact": false } } } } PUT my_index/_doc/1 { "pagerank": 8, "url_length": 22 } GET my_index/_search { "query": { "rank_feature": { "field": "pagerank" } } }
Rank feature fields must use the |
|
Rank features that correlate negatively with the score need to declare it |
rank_feature
fields only support single-valued fields and strictly positive
values. Multi-valued fields and negative values will be rejected.
rank_feature
fields do not support querying, sorting or aggregating. They may
only be used within rank_feature
queries.
rank_feature
fields only preserve 9 significant bits for the precision, which
translates to a relative error of about 0.4%.
Rank features that correlate negatively with the score should set
positive_score_impact
to false
(defaults to true
). This will be used by
the rank_feature
query to modify the scoring formula
in such a way that the score decreases with the value of the feature instead of
increasing. For instance in web search, the url length is a commonly used
feature which correlates negatively with scores.