文章目录
概述
继续跟中华石杉老师学习ES,第15篇
官网
https://www.elastic.co/guide/en/elasticsearch/reference/current/copy-to.html
---------
例子
新增字段,用作测试
PUT /forum/_mapping/article
{
"properties": {
"new_author_first_name": {
"type": "text",
"copy_to": "new_author_full_name"
},
"new_author_last_name": {
"type": "text",
"copy_to": "new_author_full_name"
},
"new_author_full_name": {
"type": "text"
}
}
}
更新数据
POST /forum/article/_bulk
{ "update": { "_id": "1"} }
{ "doc" : {"new_author_first_name" : "Peter", "new_author_last_name" : "Smith"} }
{ "update": { "_id": "2"} }
{ "doc" : {"new_author_first_name" : "Smith", "new_author_last_name" : "Williams"} }
{ "update": { "_id": "3"} }
{ "doc" : {"new_author_first_name" : "Jack", "new_author_last_name" : "Ma"} }
{ "update": { "_id": "4"} }
{ "doc" : {"new_author_first_name" : "Robbin", "new_author_last_name" : "Li"} }
{ "update": { "_id": "5"} }
{ "doc" : {"new_author_first_name" : "Tonny", "new_author_last_name" : "Peter Smith"} }
查询
GET /forum/article/_search
{
"query": {
"match": {
"new_author_full_name": "Peter Smith"
}
}
}
返回结果
{
"took": 3,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 2.3258216,
"hits": [
{
"_index": "forum",
"_type": "article",
"_id": "1",
"_score": 2.3258216,
"_source": {
"articleID": "XHDK-A-1293-#fJ3",
"userID": 1,
"hidden": false,
"postDate": "2017-01-01",
"tag": [
"java",
"hadoop"
],
"tag_cnt": 2,
"view_cnt": 30,
"title": "this is java and elasticsearch blog",
"content": "i like to write best elasticsearch article",
"sub_title": "learning more courses",
"author_first_name": "Peter",
"author_last_name": "Smith",
"new_author_last_name": "Smith",
"new_author_first_name": "Peter"
}
},
{
"_index": "forum",
"_type": "article",
"_id": "5",
"_score": 1.7770995,
"_source": {
"articleID": "DHJK-B-1395-#Ky5",
"userID": 3,
"hidden": false,
"postDate": "2019-05-01",
"tag": [
"elasticsearch"
],
"tag_cnt": 1,
"view_cnt": 10,
"title": "this is spark blog",
"content": "spark is best big data solution based on scala ,an programming language similar to java",
"sub_title": "haha, hello world",
"author_first_name": "Tonny",
"author_last_name": "Peter Smith",
"new_author_last_name": "Peter Smith",
"new_author_first_name": "Tonny"
}
}
]
}
}
总结
cross field的问题,是否解决了呢?
问题1:只是找到尽可能多的field匹配的doc,而不是某个field完全匹配的doc
答: 解决,最匹配的document被最先返回
问题2:most_fields,没办法用minimum_should_match去掉长尾数据,就是匹配的特别少的结果
答: 解决,可以使用minimum_should_match去掉长尾数据
问题3:TF/IDF算法,比如Peter Smith和Smith Williams,搜索Peter
Smith的时候,由于first_name中很少有Smith的,所以query在所有document中的频率很低,得到的分数很高,可能Smith Williams反而会排在Peter Smith前面答: 解决,Smith和Peter在一个field了,所以在所有document中出现的次数是均匀的,不会有极端的偏差