.. _es-guide-reference-query-dsl-fuzzy-query:

===========
Fuzzy Query
===========

A fuzzy based query that uses similarity based on Levenshtein (edit distance) algorithm.


Note
    Warning: this query is not very scalable with its default prefix length of 0 - in this case, *every* term will be enumerated and cause an edit score calculation or **max_expansions** is not set.


Here is a simple example:

.. code-block:: js


    {
        "fuzzy" : { "user" : "ki" }
    }


More complex settings can be set (the values here are the default values):


.. code-block:: js


        {
            "fuzzy" : { 
                "user" : {
                    "value" : "ki",
                    "boost" : 1.0,
                    "min_similarity" : 0.5,
                    "prefix_length" : 0
                }
            }
        }


The **max_expansions** parameter (unbounded by default) controls the number of terms the fuzzy query will expand to.


Numeric / Date Fuzzy
--------------------

**fuzzy** query on a numeric field will result in a range query "around" the value using the **min_similarity** value. For example:


.. code-block:: js


    {
        "fuzzy" : {
            "price" : {
                "value" : 12,
                "min_similarity" : 2
            }
        }
    }


Will result in a range query between 10 and 14. Same applies to dates, with support for time format for the **min_similarity** field:


.. code-block:: js


    {
        "fuzzy" : {
            "created" : {
                "value" : "2010-02-05T12:05:07",
                "min_similarity" : "1d"
            }
        }
    }


In the mapping, numeric and date types now allow to configure a **fuzzy_factor** mapping value (defaults to 1), which will be used to multiply the fuzzy value by it when used in a **query_string** type query. For example, for dates, a fuzzy factor of "1d" will result in multiplying whatever fuzzy value provided in the min_similarity by it. Note, this is explicitly supported since query_string query only allowed for similarity valued between 0.0 and 1.0.