本文来自极客时间《Elasticsearch核心技术实战》 课程学习笔记,感兴趣的同学可以订阅该课程
elasticsearch 是面向文档的,文档是所有可搜索数据的最小单位
例如:
文档会被序列化为JSON格式,保存在Elasticsearch中
每个文档都有一个Unique ID
movieId,title,genres 1,Toy Story(1995),AdvenTure|Animation|Children|Comedy|Fantasy 复制代码
{ "year" : 1995, "@version" : 1, "genres" : [ "AdvenTure","Animation", "Children","Comedy","Fantasy" ], "id" : "1", "title" : "Tony Story" } 复制代码
{ "_index" : "movies", "_type" : "_doc", "_id" : "1", "_score" : "14.626", "_source" : { "year" : 1995, "@version" : 1, "genres" : [ "AdvenTure","Animation", "Children","Comedy","Fantasy" ], "id" : "1", "title" : "Tony Story" } } 复制代码
{ "movies" : { "settings" : { "index" : { "create_date" : "15526261177", "number_of_shards" : "2", "number_of_replicas" : "0", "uuid" : "", "verison" : { "created" : "302302" }, "provided_name" : "movies" } } } } 复制代码
一个Elasticsearch 集群中,可以创建很多个不同的索引
保存一个文档到Elasticsearch的过程也叫索引(indexing)
一个B树索引,一个倒排索引
RDBMS | Elasticsearch |
---|---|
Table | Index(Type) |
Row | Document |
Column | Field |
Schema | Mapping |
SQL | DSL |
1.7.0之前,一个index可以设置多个types
2.目前Type已经被Deprecated,7.0开始,一个索引只能创建一个Type-"_doc"
3.传统关系型数据库和Elasticsearch的区别
一些基本的API
原文地址
cbaj.gitee.io/blog/2020/0…