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This article introduces the relevant knowledge of "introduction to the four categories of NoSQL database". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Four categories of NoSQL databases:

Key value (Key-Value) stores the database:

This type of database mainly uses a hash table with a specific key and a pointer to specific data. The advantage of Key/value model for IT system is that it is simple and easy to deploy. But if DBA queries or updates only some of the values, Key/value is inefficient. [3] for example: Tokyo Cabinet/Tyrant, Redis, Voldemort, Oracle BDB.

Column storage database:

This part of the database is usually used to deal with the massive data of distributed storage. Keys still exist, but they are characterized by pointing to multiple columns. These columns are arranged by the column family. Such as: Cassandra, HBase, Riak.

Document database:

The document database is inspired by Lotus Notes office software, and it is similar to the first key-value storage. This type of data model is a versioned document, with semi-structured documents stored in a specific format, such as JSON. A document database can be seen as an upgraded version of a key-value database, allowing nesting of key values between them. And the query efficiency of document database is higher than that of key database. Such as: CouchDB, MongoDb. There is also a document-based database SequoiaDB in China, which has been open source.

Graphics (Graph) database:

The database of graphic structure is different from the SQL database of other rows and rows and rigid structure, it uses flexible graphical model and can be extended to multiple servers. NoSQL database does not have a standard query language (SQL), so it is necessary to develop a data model for database query. Many NoSQL databases have REST-style data interfaces or query API. [2] such as Neo4J, InfoGrid, Infinite Graph.

Therefore, we conclude that NoSQL database is more applicable in the following situations: 1, the data model is relatively simple; 2, the need for a more flexible IT system; 3, higher requirements for database performance; 4, do not need a high degree of data consistency; 5, for a given key, it is easier to map complex values of the environment.

Analysis of four classified tables in NoSQL Database

classification

An example of Examples

Typical application scenario

Data model

Advantages

Shortcoming

Key value (key-value)

Tokyo Cabinet/Tyrant, Redis, Voldemort, Oracle BDB

Content caching is mainly used to handle the high access load of a large amount of data, but also for some log systems, and so on.

Key points to the key-value pair of Value, which is usually implemented in hash table

Search speed is fast.

Data is unstructured and is usually treated only as string or binary data

Column storage database

Cassandra, HBase, Riak

Distributed file system

Store the same column of data together in a column cluster

Fast search speed, strong expansibility, and easier distributed expansion

The function is relatively limited

Document database

CouchDB, MongoDb

Web application (similar to Key-Value, Value is structured, except that the database can understand the contents of Value)

The key-value pair corresponding to Key-Value. Value is structured data.

The data structure is not strict, the table structure is variable, and there is no need to define the table structure in advance like the relational database.

Query performance is not high, and lack of unified query syntax.

Graphics (Graph) database [3]

Neo4J, InfoGrid, Infinite Graph

Social networks, recommendation systems, etc. Focus on building a relationship map

Graph structure

The graph structure correlation algorithm is used. Such as shortest path addressing, N-degree relation search, etc.

In many cases, it is necessary to calculate the whole diagram to get the required information, and this structure is not very good for distributed cluster solutions. [3]

This is the end of the introduction to the four categories of NoSQL database. Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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