Request Body Search

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

GET /twitter/_search
{
    "query" : {
        "term" : { "user" : "kimchy" }
    }
}

And here is a sample response:

{
    "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
                }
            }
        ]
    }
}

Parameters

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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 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 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.

ccs_minimize_roundtrips
Defaults to true. Set to false to disable minimizing network round-trips between the coordinating node and the remote clusters when executing cross-cluster search requests. See Cross-cluster search reduction for more.

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.

Fast check for any matching docs

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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).

GET /_search?q=message:number&size=0&terminate_after=1

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.

{
  "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": []
  }
}

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.