Document boosting with function score query

doc-boost-function-score.sh

curl -XDELETE 'localhost:9200/test'

curl -XPUT 'localhost:9200/test/doc/1' -d '
{   
    "sentence" : "less important",
    "boost" : 0.5
}
'

curl -XPUT 'localhost:9200/test/doc/2' -d '
{   
    "sentence" : "quite important",
    "boost" : 2.0
}
'

curl -XPUT 'localhost:9200/test/doc/3' -d '
{   
    "sentence" : "more important",
    "boost" : 3.0
}
'

curl -XPUT 'localhost:9200/test/doc/4' -d '
{   
    "sentence" : "who cares about this document",
    "boost" : 1.0
}
'

curl 'localhost:9200/test/_refresh'

# boost as linear decay function

curl -XPOST 'localhost:9200/test/_search' -d '
{
    "query": {
       "function_score": {
          "query" : {
              "query_string" : {
                    "query" : "sentence:important"
              }
           }, 
          "functions": [
             {
                "filter": {
                   "range": {
                      "boost": {
                         "gte": 0.0,
                         "lte": 10.0
                      }
                   }
                },
                "linear": {
                   "boost": {
                      "origin": 10,
                      "scale": 10,
                      "decay": 0.1
                   }
                }
             }
          ],
          "boost" : 100.0, 
          "max_boost" : 10.0,
          "boost_mode" : "multiply", 
          "score_mode": "multiply"
       }
    }
}
'

# boost with script_score

curl -XPOST 'localhost:9200/test/_search' -d '
{
    "query": {
       "function_score": {
          "query" : {
              "query_string" : {
                    "query" : "sentence:important"
              }
           }, 
          "functions": [
             {
                "filter": {
                   "range": {
                      "boost": {
                         "gte": 0.0,
                         "lte": 10.0
                      }
                   }
                },
                "script_score" : {
                    "script" : "_score * doc[\"boost\"].value"
                }
             }
          ],
          "boost" : 100.0, 
          "max_boost" : 10.0,
          "boost_mode" : "multiply", 
          "score_mode": "multiply"
       }
    }
}
'