[[search-your-data]]
= Search your data

[[search-query]]
A _search query_, or _query_, is a request for information about data in
{es} data streams or indices.

You can think of a query as a question, written in a way {es} understands.
Depending on your data, you can use a query to get answers to questions like:

* What processes on my server take longer than 500 milliseconds to respond?
* What users on my network ran `regsvr32.exe` within the last week?
* What pages on my website contain a specific word or phrase?

A _search_ consists of one or more queries that are combined and sent to {es}.
Documents that match a search's queries are returned in the _hits_, or
_search results_, of the response.

A search may also contain additional information used to better process its
queries. For example, a search may be limited to a specific index or only return
a specific number of results.

[discrete]
[[run-an-es-search]]
== Run a search

You can use the <<search-search,search API>> to search and
<<search-aggregations,aggregate>> data stored in {es} data streams or indices.
The API's `query` request body parameter accepts queries written in
<<query-dsl,Query DSL>>.

The following request searches `my-index-000001` using a
<<query-dsl-match-query,`match`>> query. This query matches documents with a
`user.id` value of `kimchy`.

[source,console]
----
GET /my-index-000001/_search
{
  "query": {
    "match": {
      "user.id": "kimchy"
    }
  }
}
----
// TEST[setup:my_index]

The API response returns the top 10 documents matching the query in the
`hits.hits` property.

[source,console-result]
----
{
  "took": 5,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1.3862942,
    "hits": [
      {
        "_index": "my-index-000001",
        "_type": "_doc",
        "_id": "kxWFcnMByiguvud1Z8vC",
        "_score": 1.3862942,
        "_source": {
          "@timestamp": "2099-11-15T14:12:12",
          "http": {
            "request": {
              "method": "get"
            },
            "response": {
              "bytes": 1070000,
              "status_code": 200
            },
            "version": "1.1"
          },
          "message": "GET /search HTTP/1.1 200 1070000",
          "source": {
            "ip": "127.0.0.1"
          },
          "user": {
            "id": "kimchy"
          }
        }
      }
    ]
  }
}
----
// TESTRESPONSE[s/"took": 5/"took": "$body.took"/]
// TESTRESPONSE[s/"_id": "kxWFcnMByiguvud1Z8vC"/"_id": "$body.hits.hits.0._id"/]

[discrete]
[[common-search-options]]
=== Common search options

You can use the following options to customize your searches.

*Query DSL* +
<<query-dsl,Query DSL>> supports a variety of query types you can mix and match
to get the results you want. Query types include:

* <<query-dsl-bool-query,Boolean>> and other <<compound-queries,compound
queries>>, which let you combine queries and match results based on multiple
criteria
* <<term-level-queries,Term-level queries>> for filtering and finding exact matches
* <<full-text-queries,Full text queries>>, which are commonly used in search
engines
* <<geo-queries,Geo>> and <<shape-queries,spatial queries>>

*Aggregations* +
You can use <<search-aggregations,search aggregations>> to get statistics and
other analytics for your search results. Aggregations help you answer questions
like:

* What's the average response time for my servers?
* What are the top IP addresses hit by users on my network?
* What is the total transaction revenue by customer?

*Search multiple data streams and indices* +
You can use comma-separated values and grep-like index patterns to search
several data streams and indices in the same request. You can even boost search
results from specific indices. See <<search-multiple-indices>>.

*Paginate search results* +
By default, searches return only the top 10 matching hits. To retrieve
more or fewer documents, see <<paginate-search-results>>.

*Retrieve selected fields* +
The search response's `hit.hits` property includes the full document
<<mapping-source-field,`_source`>> for each hit. To retrieve only a subset of
the `_source` or other fields, see <<search-fields>>.

*Sort search results* +
By default, search hits are sorted by `_score`, a <<relevance-scores,relevance
score>> that measures how well each document matches the query. To customize the
calculation of these scores, use the
<<query-dsl-script-score-query,`script_score`>> query. To sort search hits by
other field values, see <<sort-search-results>>.

*Run an async search* +
{es} searches are designed to run on large volumes of data quickly, often
returning results in milliseconds. For this reason, searches are
_synchronous_ by default. The search request waits for complete results before
returning a response.

However, complete results can take longer for searches across
<<frozen-indices,frozen indices>> or <<modules-cross-cluster-search,multiple
clusters>>.

To avoid long waits, you can use run an _asynchronous_, or _async_, search
instead. An <<async-search-intro,async search>> lets you retrieve partial
results for a long-running search now and get complete results later.

[discrete]
[[search-timeout]]
=== Search timeout

By default, search requests don't time out. The request waits for complete
results before returning a response.

While <<async-search-intro,async search>> is designed for long-running
searches, you can also use the `timeout` parameter to specify a duration you'd
like to wait for a search to complete. If no response is received before this
period ends, the request fails and returns an error.

[source,console]
----
GET /my-index-000001/_search
{
  "timeout": "2s",
  "query": {
    "match": {
      "user.id": "kimchy"
    }
  }
}
----
// TEST[setup:my_index]

To set a cluster-wide default timeout for all search requests, configure
`search.default_search_timeout` using the <<cluster-update-settings,cluster
settings API>>. This global timeout duration is used if no `timeout` argument is
passed in the request. If the global search timeout expires before the search
request finishes, the request is cancelled using <<task-cancellation,task
cancellation>>. The `search.default_search_timeout` setting defaults to `-1` (no
timeout).

[discrete]
[[global-search-cancellation]]
=== Search cancellation

You can cancel a search request using the <<task-cancellation,task management
API>>. {es} also automatically cancels a search request when your client's HTTP
connection closes. We recommend you set up your client to close HTTP connections
when a search request is aborted or times out.

include::request/track-total-hits.asciidoc[]
include::quickly-check-for-matching-docs.asciidoc[]

include::request/collapse.asciidoc[]
include::filter-search-results.asciidoc[]
include::request/highlighting.asciidoc[]
include::{es-repo-dir}/async-search.asciidoc[]
include::{es-repo-dir}/search/near-real-time.asciidoc[]
include::paginate-search-results.asciidoc[]
include::request/inner-hits.asciidoc[]
include::search-fields.asciidoc[]
include::{es-repo-dir}/modules/cross-cluster-search.asciidoc[]
include::search-multiple-indices.asciidoc[]
include::search-shard-routing.asciidoc[]
include::request/sort.asciidoc[]
