Fuzzy Query

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The fuzzy query uses similarity based on Levenshtein edit distance.

String fields

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The fuzzy query generates matching terms that are within the maximum edit distance specified in fuzziness and then checks the term dictionary to find out which of those generated terms actually exist in the index. The final query uses up to max_expansions matching terms.

Here is a simple example:

GET /_search
{
    "query": {
       "fuzzy" : { "user" : "ki" }
    }
}

Or with more advanced settings:

GET /_search
{
    "query": {
        "fuzzy" : {
            "user" : {
                "value": "ki",
                "boost": 1.0,
                "fuzziness": 2,
                "prefix_length": 0,
                "max_expansions": 100
            }
        }
    }
}
Parameters
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fuzziness

The maximum edit distance. Defaults to AUTO. See Fuzziness.

prefix_length

The number of initial characters which will not be “fuzzified”. This helps to reduce the number of terms which must be examined. Defaults to 0.

max_expansions

The maximum number of terms that the fuzzy query will expand to. Defaults to 50.

transpositions

Whether fuzzy transpositions (abba) are supported. Default is false.

This query can be very heavy if prefix_length is set to 0 and if max_expansions is set to a high number. It could result in every term in the index being examined!