2

I have this ES query: 

{
  "query": {
    "bool": {
      "should": [
        {
          "multi_match": {
            "query": "test",
            "fields": [
              "name^-1.0",
              "id^-1.0",
              "address.city^-1.0",
              "address.street^-1.0"
            ],
            "type": "phrase_prefix",
            "lenient": "true"
          }
        }
      ],
      "boost": 1.0,
      "minimum_should_match": "1"
    }
  },
  "from": 0,
  "size": 20
}

and currently what happens is, when I search for person with the name john, I will get bunch of results that the id, address.city, address.street contains john in them, which is fine, but I want name to be more important, and also if I have in the es 2 people john and someone with 2 names like george john I would want the just john to come up first.

can I do that? :)

JohnBigs
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1 Answers1

4

To make any field more important than other(s), you can set its boost to a higher value. So if fieldA^4 and fieldB^1 it implies that fieldA is 4 times more important than fieldB. Therefore you can give higher boost value to name field to make it more important for scoring.

For second point the document with name field value as john will have higher score than with a document having name field value as george john (assuming that other fields have same data in both documents). The reason you are get the second doc (george john) higher in result is because you have boosted all the fields with negative value.

So to cater to both of your points

  • give higher boost to name
  • make boost for all fields as positive value.

So the query should look as below:

{
  //"explain": true,
  "query": {
    "bool": {
      "should": [
        {
          "multi_match": {
            "query": "john",
            "fields": [
              "name^4.0",
              "id^1.0",
              "address.city^1.0",
              "address.street^1.0"
            ],
            "type": "phrase_prefix",
            "lenient": "true"
          }
        }
      ],
      "boost": 1,
      "minimum_should_match": "1"
    }
  },
  "from": 0,
  "size": 20
}

To understand more on how the score for the matching document is calculated by elastic, you can use the "explain": true in your query. This will give detailed steps in result, taken by elastic to calculate the score.

Nishant
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  • Nice explanation. How it would look like if each field have different query? ex. name: john address: some address – Vladimir Djukic Feb 15 '20 at 10:07
  • @VladimirDjukic In that case there would be two queries inside should/must clause as per the requirement. In each query target fields could be different or even same and that too depends. But you might have different boost levels for fields in each of these query based on the preference. – Nishant Feb 16 '20 at 04:24