Fix fuzziness for ElasticSearch/OpenSearch query

Question

I'm having issues trying to do a simple query, please see the following data:

Having this data:

POST test/_doc/1
{
  "id": 1,
  "title": "Test Name"
}

POST test/_doc/2
{
  "id": 2,
  "title": "TestName"
}

And this query:

GET test/_search
{
  "query": {
    "match": {
      "title": {
        "query": "TestName",
        "fuzziness": "AUTO"
      }
    }
  }
}

With this output:

{
  ...
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1.605183,
    "hits": [
      {
        "_index": "test",
        "_id": "2",
        "_score": 1.605183,
        "_source": {
          "id": 2,
          "title": "TestName"
        }
      }
    ]
  }
}

Why the output doesn't return both records?

How can I fix it?

Answer 1

So the solution was done with elasticsearch edge n-gram, I also had to add filter lowercase to the analyzer.

Thanks @paulo !

PUT test
{
  "mappings": {
    "properties": {
      "title": {
        "type": "text",
        "fields": {
          "edge_ngram": {
            "type": "text",
            "analyzer": "edge_ngram_analyzer"
          }
        }
      }
    }
  },
  "settings": {
    "analysis": {
      "analyzer": {
        "edge_ngram_analyzer": {
          "tokenizer": "edge_ngram_tokenizer",
          "filter": [
            "lowercase"
          ]
        }
      },
      "tokenizer": {
        "edge_ngram_tokenizer": {
          "type": "edge_ngram",
          "min_gram": 3,
          "max_gram": 10,
          "token_chars": [
            "letter",
            "digit"
          ]
        }
      }
    }
  }
}

POST test/_doc/1
{
  "title": "Test Name"
}

POST test/_doc/2
{
  "title": "TestName"
}

GET test/_search
{
  "query": {
    "match": {
      "title.edge_ngram": {
        "query": "Test Name",
        "fuzziness": "AUTO"
      }
    }
  }
}

Now it returns the expected output:

{
  ...
  "hits": {
    "total": {
      "value": 2,
      "relation": "eq"
    },
    "max_score": 3.1782691,
    "hits": [
      {
        "_index": "test",
        "_id": "1",
        "_score": 3.1782691,
        "_source": {
          "title": "Test Name"
        }
      },
      {
        "_index": "test",
        "_id": "2",
        "_score": 0.68817455,
        "_source": {
          "title": "TestName"
        }
      }
    ]
  }
}