Get API

The get API allows to get a typed JSON document from the index based on its id. The following example gets a JSON document from an index called twitter, under a type called tweet, with id valued 1:

curl -XGET 'http://localhost:9200/twitter/tweet/1'

The result of the above get operation is:

{
    "_index" : "twitter",
    "_type" : "tweet",
    "_id" : "1",
    "_version" : 1,
    "found": true,
    "_source" : {
        "user" : "kimchy",
        "postDate" : "2009-11-15T14:12:12",
        "message" : "trying out Elasticsearch"
    }
}

The above result includes the _index, _type, _id and _version of the document we wish to retrieve, including the actual _source of the document if it could be found (as indicated by the found field in the response).

The API also allows to check for the existence of a document using HEAD, for example:

curl -XHEAD -i 'http://localhost:9200/twitter/tweet/1'

By default, the get API is realtime, and is not affected by the refresh rate of the index (when data will become visible for search).

In order to disable realtime GET, one can either set realtime parameter to false, or globally default it to by setting the action.get.realtime to false in the node configuration.

When getting a document, one can specify fields to fetch from it. They will, when possible, be fetched as stored fields (fields mapped as stored in the mapping). When using realtime GET, there is no notion of stored fields (at least for a period of time, basically, until the next flush), so they will be extracted from the source itself (note, even if source is not enabled). It is a good practice to assume that the fields will be loaded from source when using realtime GET, even if the fields are stored.

The get API allows for _type to be optional. Set it to _all in order to fetch the first document matching the id across all types.

By default, the get operation returns the contents of the _source field unless you have used the fields parameter or if the _source field is disabled. You can turn off _source retrieval by using the _source parameter:

curl -XGET 'http://localhost:9200/twitter/tweet/1?_source=false'

If you only need one or two fields from the complete _source, you can use the _source_include & _source_exclude parameters to include or filter out that parts you need. This can be especially helpful with large documents where partial retrieval can save on network overhead. Both parameters take a comma separated list of fields or wildcard expressions. Example:

curl -XGET 'http://localhost:9200/twitter/tweet/1?_source_include=*.id&_source_exclude=entities'

If you only want to specify includes, you can use a shorter notation:

curl -XGET 'http://localhost:9200/twitter/tweet/1?_source=*.id,retweeted'

The get operation allows specifying a set of stored fields that will be returned by passing the fields parameter. For example:

curl -XGET 'http://localhost:9200/twitter/tweet/1?fields=title,content'

For backward compatibility, if the requested fields are not stored, they will be fetched from the _source (parsed and extracted). This functionality has been replaced by the source filtering parameter.

Field values fetched from the document it self are always returned as an array. Metadata fields like _routing and _parent fields are never returned as an array.

Also only leaf fields can be returned via the field option. So object fields can’t be returned and such requests will fail.

If no refresh occurred between indexing and refresh, GET will access the transaction log to fetch the document. However, some fields are generated only when indexing. If you try to access a field that is only generated when indexing, you will get an exception (default). You can choose to ignore field that are generated if the transaction log is accessed by setting ignore_errors_on_generated_fields=true.

Use the /{index}/{type}/{id}/_source endpoint to get just the _source field of the document, without any additional content around it. For example:

curl -XGET 'http://localhost:9200/twitter/tweet/1/_source'

You can also use the same source filtering parameters to control which parts of the _source will be returned:

curl -XGET 'http://localhost:9200/twitter/tweet/1/_source?_source_include=*.id&_source_exclude=entities'

Note, there is also a HEAD variant for the _source endpoint to efficiently test for document existence. Curl example:

curl -XHEAD -i 'http://localhost:9200/twitter/tweet/1/_source'

When indexing using the ability to control the routing, in order to get a document, the routing value should also be provided. For example:

curl -XGET 'http://localhost:9200/twitter/tweet/1?routing=kimchy'

The above will get a tweet with id 1, but will be routed based on the user. Note, issuing a get without the correct routing, will cause the document not to be fetched.

Controls a preference of which shard replicas to execute the get request on. By default, the operation is randomized between the shard replicas.

The preference can be set to:

The refresh parameter can be set to true in order to refresh the relevant shard before the get operation and make it searchable. Setting it to true should be done after careful thought and verification that this does not cause a heavy load on the system (and slows down indexing).

The get operation gets hashed into a specific shard id. It then gets redirected to one of the replicas within that shard id and returns the result. The replicas are the primary shard and its replicas within that shard id group. This means that the more replicas we will have, the better GET scaling we will have.

You can use the version parameter to retrieve the document only if it’s current version is equal to the specified one. This behavior is the same for all version types with the exception of version type FORCE which always retrieves the document.

Internally, Elasticsearch has marked the old document as deleted and added an entirely new document. The old version of the document doesn’t disappear immediately, although you won’t be able to access it. Elasticsearch cleans up deleted documents in the background as you continue to index more data.