IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.
« IDs Range query »
Elastic Docs ›Elasticsearch Guide [8.8] ›Query DSL ›Term-level queries

Prefix query

edit

Prefix query

edit

Returns documents that contain a specific prefix in a provided field.

Example request

edit

The following search returns documents where the user.id field contains a term that begins with ki.

response = client.search(
  body: {
    query: {
      prefix: {
        "user.id": {
          value: 'ki'
        }
      }
    }
  }
)
puts response
GET /_search
{
  "query": {
    "prefix": {
      "user.id": {
        "value": "ki"
      }
    }
  }
}

Top-level parameters for prefix

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

Parameters for <field>

edit
value
(Required, string) Beginning characters of terms you wish to find in the provided <field>.
rewrite
(Optional, string) Method used to rewrite the query. For valid values and more information, see the rewrite parameter.
case_insensitive [7.10.0] Added in 7.10.0.
(Optional, Boolean) Allows ASCII case insensitive matching of the value with the indexed field values when set to true. Default is false which means the case sensitivity of matching depends on the underlying field’s mapping.

Notes

edit

Short request example

edit

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

response = client.search(
  body: {
    query: {
      prefix: {
        user: 'ki'
      }
    }
  }
)
puts response
GET /_search
{
  "query": {
    "prefix" : { "user" : "ki" }
  }
}

Speed up prefix queries

edit

You can speed up prefix queries using the index_prefixes mapping parameter. If enabled, Elasticsearch indexes prefixes in a separate field, according to the configuration settings. This lets Elasticsearch run prefix queries more efficiently at the cost of a larger index.

Allow expensive queries

edit

Prefix queries will not be executed if search.allow_expensive_queries is set to false. However, if index_prefixes are enabled, an optimised query is built which is not considered slow, and will be executed in spite of this setting.

« IDs Range query »