94cad286bc
In a few previous PR's we restructured the ES|QL docs to make it possible to generate them dynamically. This PR just moves a few files around to make the query languages docs easier to work with, and a little more organized like the ES|QL docs. A bit part of this was setting up redirects to the new locations, so other repo's could correctly link to the elasticsearch docs.
1.9 KiB
| navigation_title | mapped_pages | |
|---|---|---|
| Rank feature |
|
Rank feature field type [rank-feature]
A 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-000001
{
"mappings": {
"properties": {
"pagerank": {
"type": "rank_feature" <1>
},
"url_length": {
"type": "rank_feature",
"positive_score_impact": false <2>
}
}
}
}
PUT my-index-000001/_doc/1
{
"pagerank": 8,
"url_length": 22
}
GET my-index-000001/_search
{
"query": {
"rank_feature": {
"field": "pagerank"
}
}
}
- Rank feature fields must use the
rank_featurefield type - Rank features that correlate negatively with the score need to declare it
::::{note}
rank_feature fields only support single-valued fields and strictly positive values. Multi-valued fields and negative values will be rejected.
::::
::::{note}
rank_feature fields do not support querying, sorting or aggregating. They may only be used within rank_feature queries.
::::
::::{note}
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.