概述
继续跟中华石杉老师学习ES，第十一篇
课程地址： https://www.roncoo.com/view/55
官方文档
https://www.elastic.co/guide/en/elasticsearch/guide/current/_tuning_best_fields_queries.html
https://www.elastic.co/guide/en/elasticsearch/reference/7.2/query-dsl-dis-max-query.html
例子
数据同 上篇博文 构造索引的DSL
这次我们使用dis_max查询 java beginner , DSL如下
GET /forum/article/_search { "query": { "dis_max": { "queries": [ { "match": { "title": "java beginner" } }, { "match": { "content": "java beginner" } } ] } } }
返回
{ "took": 2, "timed_out": false, "_shards": { "total": 1, "successful": 1, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 1.0341108, "hits": [ { "_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": "2", "_score": 0.93952733, "_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": 0.79423964, "_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": "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" } }, { "_index": "forum", "_type": "article", "_id": "1", "_score": 0.4889865, "_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" } } ] } }
不知道为啥id=3的相关度是最高的… 如果有知道的，烦请不吝赐教。
dis_max只取某一个query最大的分数，完全不考虑其他query的分数
tie_breaker
使用tie_breaker将其他query的分数也考虑进去
tie_breaker参数的意义，在于说，将其他query的分数，乘以tie_breaker，然后综合与最高分数的那个query的分数，综合在一起进行计算，除了取最高分以外，还会考虑其他的query的分数。
tie_breaker的值，在0~1之间，是个小数。
GET /forum/article/_search { "query": { "dis_max": { "queries": [ { "match": { "title": "java beginner" } }, { "match": { "content": "java beginner" } } ], "tie_breaker": 0.7 } } }
返回结果
{ "took": 2, "timed_out": false, "_shards": { "total": 1, "successful": 1, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 1.344432, "hits": [ { "_index": "forum", "_type": "article", "_id": "2", "_score": 1.344432, "_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": 1.1365302, "_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": "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" } }, { "_index": "forum", "_type": "article", "_id": "1", "_score": 0.4889865, "_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" } } ] } }
