Elasricsearch 优化Terms聚合的性能

Warm up global ordinals
Global ordinals are a data-structure that is used in order to run terms aggregations on keyword fields. They are loaded lazily in memory because Elasticsearch does not know which fields will be used in terms aggregations and which fields won’t. You can tell Elasticsearch to load global ordinals eagerly at refresh-time by configuring mappings as described below:

PUT index
{
  "mappings": {
    "properties": {
      "foo": {
        "type": "keyword",
        "eager_global_ordinals": true
      }
    }
  }
}

原文链接:https://www.elastic.co/guide/en/elasticsearch/reference/7.1/tune-for-search-speed.html