Elasticsearch慢速聚合(Elasticsearch Slow terms aggregation)

 我有一个ES查询和聚合的问题。 在添加术语聚合之前，所有es记录数大约为1亿个，我的查询速度很快，只需要75ms，所有命中数都是105.但是在添加聚合后，如下所示： 
 
{
    "query": {
        ...
    },
    "aggs": {
        "index": {
            "terms": {
                "field": "index"
            }
         }
     }
}
 
 这个查询将花费20秒！ 我的问题是：我的查询结果数只有105，为什么聚合太慢？ 谢谢你的回复！ 

I hava a problem with es query and aggregation. All es record count is about 0.1 billion, before adding a terms aggregation, my query is fast, only cost 75ms and all hit count is 105. But after adding a aggregation, like this one:
 
{
    "query": {
        ...
    },
    "aggs": {
        "index": {
            "terms": {
                "field": "index"
            }
         }
     }
}
 
this query will cost 20 second! My question is: my query result count is only 105, why the aggregation is so slow? Thanks for any reply!

原文：https://stackoverflow.com/questions/50893653