OpenSearch/docs/reference/search/request-body.asciidoc

[[search-request-body]]
== Request Body Search

The search request can be executed with a search DSL, which includes the
<<query-dsl,Query DSL>>, within its body. Here is an
example:

[source,js]
--------------------------------------------------
GET /twitter/_search
{
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}
--------------------------------------------------
// CONSOLE
// TEST[setup:twitter]

And here is a sample response:

[source,js]
--------------------------------------------------
{
    "took": 1,
    "timed_out": false,
    "_shards":{
        "total" : 1,
        "successful" : 1,
        "skipped" : 0,
        "failed" : 0
    },
    "hits":{
        "total" : {
            "value": 1,
            "relation": "eq"
        },
        "max_score": 1.3862944,
        "hits" : [
            {
                "_index" : "twitter",
                "_type" : "_doc",
                "_id" : "0",
                "_score": 1.3862944,
                "_source" : {
                    "user" : "kimchy",
                    "message": "trying out Elasticsearch",
                    "date" : "2009-11-15T14:12:12",
                    "likes" : 0
                }
            }
        ]
    }
}
--------------------------------------------------
// TESTRESPONSE[s/"took": 1/"took": $body.took/]

[float]
=== Parameters

[horizontal]
`timeout`::

    A search timeout, bounding the search request to be executed within the
    specified time value and bail with the hits accumulated up to that point
    when expired. Search requests are canceled after the timeout is reached using
    the <<global-search-cancellation>> mechanism.
    Defaults to no timeout. See <<time-units>>.

`from`::

    To retrieve hits from a certain offset. Defaults to `0`.

`size`::

    The number of hits to return. Defaults to `10`. If you do not care about
    getting some hits back but only about the number of matches and/or
    aggregations, setting the value to `0` will help performance.

`search_type`::

    The type of the search operation to perform. Can be
    `dfs_query_then_fetch` or `query_then_fetch`.
    Defaults to `query_then_fetch`.
    See <<search-request-search-type,_Search Type_>> for more.

`request_cache`::

    Set to `true` or `false` to enable or disable the caching
    of search results for requests where `size` is 0, ie
    aggregations and suggestions (no top hits returned).
    See <<shard-request-cache>>.

`allow_partial_search_results`::

    Set to `false` to return an overall failure if the request would produce partial 
    results. Defaults to true, which will allow partial results in the case of timeouts
    or partial failures. This default can be controlled using the cluster-level setting
    `search.default_allow_partial_results`.

`terminate_after`::

    The maximum number of documents to collect for each shard,
    upon reaching which the query execution will terminate early. If set, the
    response will have a boolean field `terminated_early` to indicate whether
    the query execution has actually terminated_early. Defaults to no
    terminate_after.

`batched_reduce_size`::

    The number of shard results that should be reduced  at once on the
    coordinating node. This value should be used as a protection  mechanism to
    reduce the memory overhead per search request if the potential  number of
    shards in the request can be large.



Out of the above, the `search_type`, `request_cache` and the `allow_partial_search_results` 
settings must be passed as query-string parameters. The rest of the search request should 
be passed within the body itself. The body content can also be passed as a REST
parameter named `source`.

Both HTTP GET and HTTP POST can be used to execute search with body. Since not
all clients support GET with body, POST is allowed as well.

[float]
=== Fast check for any matching docs

NOTE: `terminate_after` is always applied **after** the `post_filter` and stops
       the query as well as the aggregation executions when enough hits have been
       collected on the shard. Though the doc count on aggregations may not reflect
       the `hits.total` in the response since aggregations are applied **before** the
       post filtering.

In case we only want to know if there are any documents matching a
specific query, we can set the `size` to `0` to indicate that we are not
interested in the search results. Also we can set `terminate_after` to `1`
to indicate that the query execution can be terminated whenever the first
matching document was found (per shard).

[source,js]
--------------------------------------------------
GET /_search?q=message:number&size=0&terminate_after=1
--------------------------------------------------
// CONSOLE
// TEST[setup:twitter]

The response will not contain any hits as the `size` was set to `0`. The
`hits.total` will be either equal to `0`, indicating that there were no
matching documents, or greater than `0` meaning that there were at least
as many documents matching the query when it was early terminated.
Also if the query was terminated early, the `terminated_early` flag will
be set to `true` in the response.

[source,js]
--------------------------------------------------
{
  "took": 3,
  "timed_out": false,
  "terminated_early": true,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped" : 0,
    "failed": 0
  },
  "hits": {
    "total" : {
        "value": 1,
        "relation": "eq"
    },
    "max_score": null,
    "hits": []
  }
}
--------------------------------------------------
// TESTRESPONSE[s/"took": 3/"took": $body.took/]

The `took` time in the response contains the milliseconds that this request
took for processing, beginning quickly after the node received the query, up
until all search related work is done and before the above JSON is returned
to the client. This means it includes the time spent waiting in thread pools,
executing a distributed search across the whole cluster and gathering all the
results.

include::request/query.asciidoc[]

include::request/from-size.asciidoc[]

include::request/sort.asciidoc[]

include::request/track-total-hits.asciidoc[]

include::request/source-filtering.asciidoc[]

include::request/stored-fields.asciidoc[]

include::request/script-fields.asciidoc[]

include::request/docvalue-fields.asciidoc[]

include::request/post-filter.asciidoc[]

include::request/highlighting.asciidoc[]

include::request/rescore.asciidoc[]

include::request/search-type.asciidoc[]

include::request/scroll.asciidoc[]

include::request/preference.asciidoc[]

include::request/explain.asciidoc[]

include::request/version.asciidoc[]

include::request/index-boost.asciidoc[]

include::request/min-score.asciidoc[]

include::request/named-queries-and-filters.asciidoc[]

include::request/inner-hits.asciidoc[]

include::request/collapse.asciidoc[]

include::request/search-after.asciidoc[]