The top hit aggregation is different from the other aggregation types. All the previous aggregations have metric (simple values) or bucket values; the top hit aggregation returns buckets of search hits.
Generally, the top hit aggregation is used as a subaggregation so that the top matching documents can be aggregated in buckets.
You need a working ElasticSearch cluster and an index populated with the script (chapter_06/executing_top_hit_aggregations.sh) available at https://github.com/aparo/elasticsearch-cookbook-second-edition.
To execute a top hit aggregation, we will perform the steps given as follows:
We want to aggregate the documents hits by tag (
tags) and return only thenamefield of documents with a maximum age (top_tag_hits). We'll execute the search and aggregation with the following command:curl -XGET 'http://127.0.0.1:9200/test-index/test-type/_search' -d '{ "query": { "match_all": {} }, "size": 0, "aggs...