Elasticsearch 学习之Field Collapsing（字段折叠）

Field Collapsing（字段折叠）不能与scroll、rescore以及search after 结合使用

• collapse字段：表示按照age（每个age对应多条document结果）的值折叠（keyword或者数值）
• sort：表示按照age字段排序

• from：偏移，即前180个document的值都被折叠掉了

  curl -XGET "http://localhost:9200/bank/_search" -H 'Content-Type: application/json' -d'
  {
      "query": {
  "match": {
      "address": "Place"
  }
   },
      "collapse" : {
          "field" : "age" 
   },
      "sort": ["age"], 
      "from": 10
          }''
  

• Expand collapse results（对于每个折叠的结果，可以通过inner_hits展开结果）

  • max_concurrent_group_searches：允许每组检索inner_hits的并发请求数 (默认按照线程池的大小或者数据节点数）

  • 单个inner_hits

    curl -XGET "http://localhost:9200/bank/_search" -H 'Content-Type: application/json' -d'
    {
    "query": {
        "match": {
            "address": "Place"
        }
    },
    "collapse" : {
        "field" : "age", 
        "inner_hits": {
            "name": "test", 
            "size": 5, 
            "sort": [{ "age": "asc" }] 
        },
        "max_concurrent_group_searches": 4 
    },
    "sort": ["age"]
    }'
    

  • 多个inner_hits

    curl -XGET "http://localhost:9200/bank/_search" -H 'Content-Type: application/json' -d'
    {
        "query": {
            "match": {
                "address": "Place"
            }
        },
        "collapse" : {
            "field" : "age", 
            "inner_hits":[ {
                "name": "age", 
                "size": 2, 
                "sort": [{ "age": "asc" }] 
            },
            {
            "name":"account_number",
            "size": 2, 
            "sort": [{ "account_number": "asc" }] 
            }],
            "max_concurrent_group_searches": 4
        },
        "sort": ["age"]
    }'