Get last document from ElasticSearch

Question

so I have an elastic search index and I am sending docs to it attached with a timestamp. I am wondering if there is a way to extract the last document based on the time stamp. I.e. say to elastic give me the doc with the last time.

Thanks.

Answer 1

Yes, you can simply request one single document (size: 1) and sorted by decreasing timestamp

POST index/_search
{
   "size": 1,
   "sort": { "timestamp": "desc"},
   "query": {
      "match_all": {}
   }
}

Answer 2

Get last document from elasticsearch using java high-level REST client

The given solution is in Scala language:

import org.elasticsearch.action.search.{SearchRequest, SearchResponse}
import org.elasticsearch.index.query.QueryBuilders
import org.elasticsearch.search.builder.SearchSourceBuilder
import org.elasticsearch.search.sort.SortOrder

val searchRequest = new SearchRequest("index")
val searchSourceBuilder = new SearchSourceBuilder
val queryBuilder = QueryBuilders.boolQuery()

queryBuilder.must(QueryBuilders.termQuery("field.keyword", "field value"))

searchSourceBuilder.query(queryBuilder)
                   .sort("timestamp", SortOrder.DESC)
                   .size(1)
searchRequest.source(searchSourceBuilder)
val searchResponse = high_level_client.search(searchRequest)