Some weird problem with fuzzy query in elasticsearch

Question

I have one doc in es

        "_type": "_doc",
        "_id": "109487",
        "_score": null,
        "_source": {
          "id": "109487",
          "title": "Interstellar",
          "year": 2014,
          "genre": [
            "Sci-Fi",
            "IMAX"
          ]
        },
        "sort": [
          "Interstellar"
        ]
      }

I am searching with a fuzzy query like

{
    "query": {
        "fuzzy": {
            "title": {"value": "intersteller", "fuzziness": 1}
        }
    }
}

But the weird thing is if i am searching with small i in intersteller then i am getting the desired record with title as Interstellar but if i am searching with Capital I ie if my query is

    "query": {
        "fuzzy": {
            "title": {"value": "Intersteller", "fuzziness": 1}
        }
    }
}

then am not getting and docs from db .. just wanted to understand what is happening behind the scenes

Answer 1

The fuzzy query does not analyze the text. Mostly fuzzy query acts like a term query itself.

In your case "title" field must be using standard analyzer. So "Intersteller" is indexed as "intersteller". Now when you are performing a fuzzy query on "intersteller", you will get the result but not with "Intersteller"

To know more about fuzzy query refer to this elasticsearch blog

---

It is better to use a match query along with the fuzziness parameter

{
  "query": {
    "match": {
      "title": {
        "query": "Intersteller",
        "fuzziness": "auto"
      }
    }
  }
}

---

If you want use fuzzy query, then you need to increase the fuzziness parameter, to get your document to match

{
  "query": {
    "fuzzy": {
      "title": {
        "value": "Intersteller",
        "fuzziness": 3
      }
    }
  }
}