不爲也 比不能也

So far, we have learned how to use Elasticsearch as a simple NoSQL-style distributed document store. We can throw JSON documents at Elasticsearch and retrieve each one by ID. But the real power of Elasticsearch lies in its ability to make sense out of chaos — to turn Big Data into Big Information.지금까지, 간단한 NoSQL-style의 분산 document 저장소로서의 Elasticsearch를 사용하는 방법에 대해 배웠다. Elasticsearch에 JSON docume..

There are two forms of the search API: a "lite" query-string version that expects all its parameters to be passed in the query string, and the full request body version that expects a JSON request body and uses a rich search language called the query DSL.search API에는 두 가지 형식이 있다. 하나는 query-string 의 "아류(lite)" 버전이다. 이 버전은 모든 매개변수가 query string에 전달된다. 다른 하나는 full request body 버전이다. 이 버전은 JSON requ..

Besides the simple scalar datatypes that we have mentioned, JSON also has null values, arrays, and objects, all of which are supported by Elasticsearch.위에서 언급한 기본 데이터 type외에도, JSON은 null 값, 배열, 오브젝트도 가질 수 있다. Elasticsearch는 이들 모두를 지원한다.Multivalue FieldseditIt is quite possible that we want our tag field to contain more than one tag. Instead of a single string, we could index an array of tags:tag..

The query DSL is a flexible, expressive search language that Elasticsearch uses to expose most of the power of Lucene through a simple JSON interface. It is what you should be using to write your queries in production. It makes your queries more flexible, more precise, easier to read, and easier to debug.query DSL은 간단한 JSON interface를 이용해, Lucene을 100% 활용하기 위해, Elasticsearch가 사용하는 유연하고, 표현력 있는 검..

When Elasticsearch encounters a previously unknown field in a document, it uses dynamic mappingto determine the datatype for the field and automatically adds the new field to the type mapping.Elasticsearch가 document에서 이전에 알려지지 않은 field를 만난 경우, field의 데이터 type을 결정하고, 자동으로 type mapping에 새로운 field를 추가하기 위해, dynamic mapping을 사용한다.Sometimes this is the desired behavior and sometimes it isn’t. Perhaps..

The first challenge that had to be solved was how to make text searchable. Traditional databases store a single value per field, but this is insufficient for full-text search. Every word in a text field needs to be searchable, which means that the database needs to be able to index multiple values—words, in this case—in a single field.해결해야 할 첫 번째 과제는, 텍스트를 검색 가능하도록 만드는 방법이다. 전통적인 데이터베이스는 field당 ..