94 lines
2.8 KiB
Plaintext
94 lines
2.8 KiB
Plaintext
[[query-dsl-regexp-query]]
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=== Regexp query
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++++
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<titleabbrev>Regexp</titleabbrev>
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++++
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Returns documents that contain terms matching a
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https://en.wikipedia.org/wiki/Regular_expression[regular expression].
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A regular expression is a way to match patterns in data using placeholder
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characters, called operators. For a list of operators supported by the
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`regexp` query, see <<regexp-syntax, Regular expression syntax>>.
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[[regexp-query-ex-request]]
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==== Example request
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The following search returns documents where the `user` field contains any term
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that begins with `k` and ends with `y`. The `.*` operators match any
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characters of any length, including no characters. Matching
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terms can include `ky`, `kay`, and `kimchy`.
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[source,console]
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----
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GET /_search
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{
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"query": {
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"regexp": {
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"user": {
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"value": "k.*y",
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"flags" : "ALL",
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"max_determinized_states": 10000,
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"rewrite": "constant_score"
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}
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}
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}
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}
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----
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[[regexp-top-level-params]]
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==== Top-level parameters for `regexp`
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`<field>`::
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(Required, object) Field you wish to search.
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[[regexp-query-field-params]]
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==== Parameters for `<field>`
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`value`::
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(Required, string) Regular expression for terms you wish to find in the provided
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`<field>`. For a list of supported operators, see <<regexp-syntax, Regular
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expression syntax>>.
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+
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--
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By default, regular expressions are limited to 1,000 characters. You can change
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this limit using the <<index-max-regex-length, `index.max_regex_length`>>
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setting.
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[WARNING]
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=====
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The performance of the `regexp` query can vary based on the regular expression
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provided. To improve performance, avoid using wildcard patterns, such as `.*` or
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`.*?+`, without a prefix or suffix.
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=====
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--
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`flags`::
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(Optional, string) Enables optional operators for the regular expression. For
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valid values and more information, see <<regexp-optional-operators, Regular
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expression syntax>>.
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`max_determinized_states`::
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+
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--
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(Optional, integer) Maximum number of
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https://en.wikipedia.org/wiki/Deterministic_finite_automaton[automaton states]
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required for the query. Default is `10000`.
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{es} uses https://lucene.apache.org/core/[Apache Lucene] internally to parse
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regular expressions. Lucene converts each regular expression to a finite
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automaton containing a number of determinized states.
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You can use this parameter to prevent that conversion from unintentionally
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consuming too many resources. You may need to increase this limit to run complex
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regular expressions.
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--
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`rewrite`::
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(Optional, string) Method used to rewrite the query. For valid values and more
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information, see the <<query-dsl-multi-term-rewrite, `rewrite` parameter>>.
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==== Notes
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===== Allow expensive queries
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Regexp queries will not be executed if <<query-dsl-allow-expensive-queries, `search.allow_expensive_queries`>>
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is set to false.
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