OpenSearch/docs/reference/query-dsl/match-query.asciidoc

[[query-dsl-match-query]]
=== Match query
++++
<titleabbrev>Match</titleabbrev>
++++

Returns documents that match a provided text, number, date or boolean value. The
provided text is analyzed before matching.

The `match` query is the standard query for performing a full-text search,
including options for fuzzy matching.


[[match-query-ex-request]]
==== Example request

[source,console]
--------------------------------------------------
GET /_search
{
    "query": {
        "match" : {
            "message" : {
                "query" : "this is a test"
            }
        }
    }
}
--------------------------------------------------


[[match-top-level-params]]
==== Top-level parameters for `match`

`<field>`::
(Required, object) Field you wish to search.


[[match-field-params]]
==== Parameters for `<field>`
`query`::
+
--
(Required) Text, number, boolean value or date you wish to find in the provided
`<field>`.

The `match` query <<analysis,analyzes>> any provided text before performing a
search. This means the `match` query can search <<text,`text`>> fields for
analyzed tokens rather than an exact term.
--

`analyzer`::
(Optional, string) <<analysis,Analyzer>> used to convert the text in the `query`
value into tokens. Defaults to the <<specify-index-time-analyzer,index-time
analyzer>> mapped for the `<field>`. If no analyzer is mapped, the index's
default analyzer is used.

`auto_generate_synonyms_phrase_query`::
+
--
(Optional, boolean) If `true`, <<query-dsl-match-query-phrase,match phrase>>
queries are automatically created for multi-term synonyms. Defaults to `true`.

See <<query-dsl-match-query-synonyms,Use synonyms with match query>> for an
example.
--

`fuzziness`::
(Optional, string) Maximum edit distance allowed for matching. See <<fuzziness>>
for valid values and more information. See <<query-dsl-match-query-fuzziness>>
for an example.

`max_expansions`::
(Optional, integer) Maximum number of terms to which the query will
expand. Defaults to `50`.

`prefix_length`::
(Optional, integer) Number of beginning characters left unchanged for fuzzy
matching. Defaults to `0`.

`transpositions`::
(Optional, boolean) If `true`, edits for fuzzy matching include
transpositions of two adjacent characters (ab → ba). Defaults to `true`.

`fuzzy_rewrite`::
+
--
(Optional, string) Method used to rewrite the query. See the
<<query-dsl-multi-term-rewrite, `rewrite` parameter>> for valid values and more
information.

If the `fuzziness` parameter is not `0`, the `match` query uses a `rewrite`
method of `top_terms_blended_freqs_${max_expansions}` by default.
--

`lenient`::
(Optional, boolean) If `true`, format-based errors, such as providing a text
`query` value for a <<number,numeric>> field, are ignored. Defaults to `false`.

`operator`::
+
--
(Optional, string) Boolean logic used to interpret text in the `query` value.
Valid values are:

`OR` (Default)::
For example, a `query` value of `capital of Hungary` is interpreted as `capital
OR of OR Hungary`.

`AND`::
For example, a `query` value of `capital of Hungary` is interpreted as `capital
AND of AND Hungary`.
--

`minimum_should_match`::
+
--
(Optional, string) Minimum number of clauses that must match for a document to
be returned. See the <<query-dsl-minimum-should-match, `minimum_should_match`
parameter>> for valid values and more information.
--

`zero_terms_query`::
+
--
(Optional, string) Indicates whether no documents are returned if the `analyzer`
removes all tokens, such as when using a `stop` filter. Valid values are:

`none` (Default)::
No documents are returned if the `analyzer` removes all tokens.

`all`::
Returns all documents, similar to a <<query-dsl-match-all-query,`match_all`>>
query.

See <<query-dsl-match-query-zero>> for an example.
--


[[match-query-notes]]
==== Notes

[[query-dsl-match-query-short-ex]]
===== Short request example

You can simplify the match query syntax by combining the `<field>` and `query`
parameters. For example:

[source,console]
----
GET /_search
{
    "query": {
        "match" : {
            "message" : "this is a test"
        }
    }
}
----

[[query-dsl-match-query-boolean]]
===== How the match query works

The `match` query is of type `boolean`. It means that the text
provided is analyzed and the analysis process constructs a boolean query
from the provided text. The `operator` parameter can be set to `or` or `and`
to control the boolean clauses (defaults to `or`). The minimum number of
optional `should` clauses to match can be set using the
<<query-dsl-minimum-should-match,`minimum_should_match`>>
parameter.

Here is an example with the `operator` parameter:

[source,console]
--------------------------------------------------
GET /_search
{
    "query": {
        "match" : {
            "message" : {
                "query" : "this is a test",
                "operator" : "and"
            }
        }
    }
}
--------------------------------------------------

The `analyzer` can be set to control which analyzer will perform the
analysis process on the text. It defaults to the field explicit mapping
definition, or the default search analyzer.

The `lenient` parameter can be set to `true` to ignore exceptions caused by
data-type mismatches,  such as trying to query a numeric field with a text
query string. Defaults to `false`.

[[query-dsl-match-query-fuzziness]]
===== Fuzziness in the match query

`fuzziness` allows _fuzzy matching_ based on the type of field being queried.
See <<fuzziness>> for allowed settings.

The `prefix_length` and
`max_expansions` can be set in this case to control the fuzzy process.
If the fuzzy option is set the query will use `top_terms_blended_freqs_${max_expansions}`
as its <<query-dsl-multi-term-rewrite,rewrite
method>> the `fuzzy_rewrite` parameter allows to control how the query will get
rewritten.

Fuzzy transpositions (`ab` -> `ba`) are allowed by default but can be disabled
by setting `fuzzy_transpositions` to `false`.

NOTE: Fuzzy matching is not applied to terms with synonyms or in cases where the
analysis process produces multiple tokens at the same position. Under the hood
these terms are expanded to a special synonym query that blends term frequencies,
which does not support fuzzy expansion.

[source,console]
--------------------------------------------------
GET /_search
{
    "query": {
        "match" : {
            "message" : {
                "query" : "this is a test",
                "operator" : "and"
            }
        }
    }
}
--------------------------------------------------

[[query-dsl-match-query-zero]]
===== Zero terms query
If the analyzer used removes all tokens in a query like a `stop` filter
does, the default behavior is to match no documents at all. In order to
change that the `zero_terms_query` option can be used, which accepts
`none` (default) and `all` which corresponds to a `match_all` query.

[source,console]
--------------------------------------------------
GET /_search
{
    "query": {
        "match" : {
            "message" : {
                "query" : "to be or not to be",
                "operator" : "and",
                "zero_terms_query": "all"
            }
        }
    }
}
--------------------------------------------------

[[query-dsl-match-query-cutoff]]
===== Cutoff frequency

deprecated[7.3.0,"This option can be omitted as the <<query-dsl-match-query>> can skip blocks of documents efficiently, without any configuration, provided that the total number of hits is not tracked."]

The match query supports a `cutoff_frequency` that allows
specifying an absolute or relative document frequency where high
frequency terms are moved into an optional subquery and are only scored
if one of the low frequency (below the cutoff) terms in the case of an
`or` operator or all of the low frequency terms in the case of an `and`
operator match.

This query allows handling `stopwords` dynamically at runtime, is domain
independent and doesn't require a stopword file. It prevents scoring /
iterating high frequency terms and only takes the terms into account if a
more significant / lower frequency term matches a document. Yet, if all
of the query terms are above the given `cutoff_frequency` the query is
automatically transformed into a pure conjunction (`and`) query to
ensure fast execution.

The `cutoff_frequency` can either be relative to the total number of
documents if in the range `[0..1)` or absolute if greater or equal to
`1.0`.

Here is an example showing a query composed of stopwords exclusively:

[source,console]
--------------------------------------------------
GET /_search
{
    "query": {
        "match" : {
            "message" : {
                "query" : "to be or not to be",
                "cutoff_frequency" : 0.001
            }
        }
    }
}
--------------------------------------------------
// TEST[warning:Deprecated field [cutoff_frequency] used, replaced by [you can omit this option, the [match] query can skip block of documents efficiently if the total number of hits is not tracked]]

IMPORTANT: The `cutoff_frequency` option operates on a per-shard-level. This means
that when trying it out on test indexes with low document numbers you
should follow the advice in {defguide}/relevance-is-broken.html[Relevance is broken].

[[query-dsl-match-query-synonyms]]
===== Synonyms

The `match` query supports multi-terms synonym expansion with the <<analysis-synonym-graph-tokenfilter,
synonym_graph>> token filter. When this filter is used, the parser creates a phrase query for each multi-terms synonyms.
For example, the following synonym: `"ny, new york" would produce:`

`(ny OR ("new york"))`

It is also possible to match multi terms synonyms with conjunctions instead:

[source,console]
--------------------------------------------------
GET /_search
{
   "query": {
       "match" : {
           "message": {
               "query" : "ny city",
               "auto_generate_synonyms_phrase_query" : false
           }
       }
   }
}
--------------------------------------------------

The example above creates a boolean query:

`(ny OR (new AND york)) city`

that matches documents with the term `ny` or the conjunction `new AND york`.
By default the parameter `auto_generate_synonyms_phrase_query` is set to `true`.