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This article mainly introduces "what is the concept of Elasticsearch". In daily operation, I believe that many people have doubts about the concept of Elasticsearch. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the doubts about "what is the concept of Elasticsearch?" Next, please follow the editor to study!

Elasticsearch, distributed, high-performance, highly available, scalable search and analysis system

1. What is search?

2. What happens if you search with a database?

3. What are full-text search, inverted indexing and Lucene?

4. What is Elasticsearch?

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1. What is search?

Baidu: for example, when we want to find any information, we will search it on Baidu, for example, find a movie we like, or find a book that we like, or find a piece of news that we are interested in (mention the first impression of search).

Baidu! = search, this is wrong

Vertical search (intra-site search)

Internet search: e-commerce sites, recruitment sites, news sites, various app

IT system search: OA software, office automation software, meeting management, schedule management, project management, staff management, search "Zhang San", "Zhang San er", "Zhang Xiao San"; there is an e-commerce website, seller, background management system, search for "toothpaste", orders, "toothpaste related orders"

Search, that is, in any scenario, to find the information you want, at this time, you will enter a keyword you want to search, and then expect to find some information related to this keyword

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2. What happens if you search with a database?

If you do software development, or if you have a certain understanding of IT and computers, you all know that the data are stored in the database, such as commodity information of e-commerce websites, job information of recruitment websites, news information of news websites, and so on. So, naturally, if we consider from a technical point of view, how to achieve the internal search function of e-commerce websites, we can consider using the database to search.

1. For example, the text of the specified field of each record may be very long. For example, the length of the "product description" field is thousands or even tens of thousands of characters. At this time, all the text of each record should be scanned and lazy to judge whether you include the keyword I specified (such as "toothpaste").

2. You can't separate the search terms, and search for as many results as possible that meet your expectations. For example, if you enter "biochemical machine", you will not be able to search for "biochemical crisis".

It is not very reliable to use database to realize search. Generally speaking, the performance will be very poor.

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3. What is full-text search and Lucene?

(1) full-text retrieval, inverted indexing

(2) lucene, is a jar package, which contains a variety of encapsulated inverted index, as well as search code, including various algorithms. When we develop with java, we introduce lucene jar, and then develop based on the api of lucene. With lucene, we can index the existing data, and lucene will organize the data structure of the index on the local disk. In addition, we can also use some of the functions provided by lucene and api to target disk quotas.

What is full-text search?

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4. What is Elasticsearch?

(1) graphic analysis

What happens if you do a search with a database?

What is Elasticsearch?

At this point, the study of "what is the concept of Elasticsearch" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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