elasticsearch - 在 Elasticsearch 中，为什么会收到错误消息 "Fielddata is disabled on text fields by default"

Question

我正在尝试编写一个查询来返回唯一的城市。我的代码是:

GET /files/_doc/_search
{
  "size":"0",
  "aggs" : {
    "uniq_cities" : {
      "terms" : { "field" : "cities" }

    }
  }
}

我有如下错误消息:

Fielddata is disabled on text fields by default. Set fielddata=true on [cities] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead.

当我跑

GET /files/_doc/_mapping

我得到:

"cities" : {
  "type" : "text",
  "fields" : {
    "keyword" : {
      "type" : "keyword",
      "ignore_above" : 256
    }
  }
}

基于以上，看来我已经有了一个关键字字段。如何修复错误消息？

Answer 1

错误提示“默认情况下在文本字段上禁用字段数据”，因为您尝试在文本字段上应用聚合 cities .它还有一个子字段 keyword其数据类型为 keyword .因此，在 cities.keyword 上应用聚合。字段如下:

GET /files/_doc/_search
{
  "size":"0",
  "aggs" : {
    "uniq_cities" : {
      "terms" : { "field" : "cities.keyword" }

    }
  }
}