Filter out metadata fields and only return source fields in elasticsearch

elasticsearch

Is there a way to tell elasticsearch to not return any metadata? Currently I can select which fields I want to be returned in source. But I only want fields in source. I would prefer to not have the metadata returned as I dont need it and would save some unnecessary parsing and transport etc.

I found Elasticsearch – how to return only data, not meta information? older question where somebody commented that it wasnt possible to do it then. Wondering if this functionality has been added or is still missing?

Best Answer

response_filtering

All REST APIs accept a filter_path parameter that can be used to reduce the response returned by elasticsearch. This parameter takes a comma separated list of filters expressed with the dot notation:

curl -XGET 'localhost:9200/_search?pretty&filter_path=took,hits.hits._id,hits.hits._score'
{
  "took" : 3,
  "hits" : {
    "hits" : [
      {
        "_id" : "3640",
        "_score" : 1.0
      },
      {
        "_id" : "3642",
        "_score" : 1.0
      }
    ]
  }
}

In python

def get_all( connection, index_name, type_name ):

    query = {
        "match_all":{}
    }

    result = connection.search( index_name, type_name,
             {"query": query},
             filter_path= ["took", "hits.hits._id", "hits.hits.score"])

    return result

If you want to filter _source fields, you should consider combining the already existing _source parameter (see Get API for more details) with the filter_path parameter like this:

curl -XGET 'localhost:9200/_search?pretty&filter_path=hits.hits._source&_source=title'
{
  "hits" : {
    "hits" : [ {
      "_source":{"title":"Book #2"}
    }, {
      "_source":{"title":"Book #1"}
    }, {
      "_source":{"title":"Book #3"}
    } ]
  }
}
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