Wildcard query
Use wildcard queries to search for terms that match a wildcard pattern. Wildcard queries support the following operators.
Operator | Description |
---|---|
* | Matches zero or more characters. |
? | Matches any single character. |
case_insensitive | If true , the wildcard query is case insensitive. If false , the wildcard query is case sensitive. Optional. Default is true (case insensitive). |
For a case-sensitive search for terms that start with H
and end with Y
, use the following request:
GET shakespeare/_search
{
"query": {
"wildcard": {
"speaker": {
"value": "H*Y",
"case_insensitive": false
}
}
}
}
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If you change *
to ?
, you get no matches because ?
refers to a single character.
Wildcard queries tend to be slow because they need to iterate over a lot of terms. Avoid placing wildcard characters at the beginning of a query because it could be a very expensive operation in terms of both resources and time.
Parameters
The query accepts the name of the field (<field>
) as a top-level parameter:
GET _search
{
"query": {
"wildcard": {
"<field>": {
"value": "patt*rn",
...
}
}
}
}
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The <field>
accepts the following parameters. All parameters except value
are optional.
Parameter | Data type | Description |
---|---|---|
value | String | The wildcard pattern used for matching terms in the field specified in <field> . |
boost | Floating-point | Boosts the query by the given multiplier. Useful for searches that contain more than one query. Values in the [0, 1) range decrease relevance, and values greater than 1 increase relevance. Default is 1 . |
case_insensitive | Boolean | If true , allows case-insensitive matching of the value with the indexed field values. Default is false (case sensitivity is determined by the field’s mapping). |
rewrite | String | Determines how OpenSearch rewrites and scores multi-term queries. Valid values are constant_score , scoring_boolean , constant_score_boolean , top_terms_N , top_terms_boost_N , and top_terms_blended_freqs_N . Default is constant_score . |
If search.allow_expensive_queries is set to false
, wildcard queries are not run.