OpenSearch/docs/reference/query-dsl/match-bool-prefix-query.asc...

86 lines
2.8 KiB
Plaintext

[[query-dsl-match-bool-prefix-query]]
=== Match boolean prefix query
++++
<titleabbrev>Match boolean prefix</titleabbrev>
++++
A `match_bool_prefix` query analyzes its input and constructs a
<<query-dsl-bool-query,`bool` query>> from the terms. Each term except the last
is used in a `term` query. The last term is used in a `prefix` query. A
`match_bool_prefix` query such as
[source,console]
--------------------------------------------------
GET /_search
{
"query": {
"match_bool_prefix" : {
"message" : "quick brown f"
}
}
}
--------------------------------------------------
where analysis produces the terms `quick`, `brown`, and `f` is similar to the
following `bool` query
[source,console]
--------------------------------------------------
GET /_search
{
"query": {
"bool" : {
"should": [
{ "term": { "message": "quick" }},
{ "term": { "message": "brown" }},
{ "prefix": { "message": "f"}}
]
}
}
}
--------------------------------------------------
An important difference between the `match_bool_prefix` query and
<<query-dsl-match-query-phrase-prefix,`match_phrase_prefix`>> is that the
`match_phrase_prefix` query matches its terms as a phrase, but the
`match_bool_prefix` query can match its terms in any position. The example
`match_bool_prefix` query above could match a field containing containing
`quick brown fox`, but it could also match `brown fox quick`. It could also
match a field containing the term `quick`, the term `brown` and a term
starting with `f`, appearing in any position.
==== Parameters
By default, `match_bool_prefix` queries' input text will be analyzed using the
analyzer from the queried field's mapping. A different search analyzer can be
configured with the `analyzer` parameter
[source,console]
--------------------------------------------------
GET /_search
{
"query": {
"match_bool_prefix" : {
"message": {
"query": "quick brown f",
"analyzer": "keyword"
}
}
}
}
--------------------------------------------------
`match_bool_prefix` queries support the
<<query-dsl-minimum-should-match,`minimum_should_match`>> and `operator`
parameters as described for the
<<query-dsl-match-query-boolean,`match` query>>, applying the setting to the
constructed `bool` query. The number of clauses in the constructed `bool`
query will in most cases be the number of terms produced by analysis of the
query text.
The <<query-dsl-match-query-fuzziness,`fuzziness`>>, `prefix_length`,
`max_expansions`, `fuzzy_transpositions`, and `fuzzy_rewrite` parameters can
be applied to the `term` subqueries constructed for all terms but the final
term. They do not have any effect on the prefix query constructed for the
final term.