请教各位，加上排序后检索速度很慢

GET index_name/_search

{

    "size":10,

    "query":{

        "match_all": {}

    }

    ,

    "sort":[

        {

            "occurred_at":{

                "order":"desc"

            }

        },

        {

            "record_id.keyword":{

                "order":"asc"

            }

        }

    ]

}

排序字段mapping信息

"occurred_at" : {

  "type" : "date",

  "format" : "yyyy-MM-dd HH:mm:ss.S||yyyy-MM-dd HH:mm:ss.SS||yyyy-MM-dd HH:mm:ss.SSS||yyyy-MM-dd HH:mm:ss||strict_date_optional_time||date_time||epoch_millis"

}

"record_id" : {

  "type" : "text",

  "fields" : {

    "keyword" : {

      "type" : "keyword",

      "ignore_above" : 256

    }

  }

}