NoSQL learns a

1, NoSQL, refers to the non-relational database. With the rise of internet web2.0 website, the traditional relational database in coping with web2.0 website, especially the web2.0 pure dynamic website of ultra-large-scale and high-concurrency SNS type, has been unable to overcome, exposing a lot of difficult problems, and the non-relational database has been developed very rapidly because of its own characteristics. NoSQL databases are created to address the challenges of multiple data types in large-scale data sets, especially big data application challenges. Although the NoSQL buzzwords have been burning for just a year, there is no denying that the second generation movement has begun. Although the early stack code can only be considered an experiment, the present system is more mature and stable. But now there is a grim fact: technology is getting more mature--so much so that the good NoSQL data store has to be rewritten, and a few think it's called version 2.0. Here are some of the more well-known tools to build fast, extensible repositories for big data.

2. Chinese name

Non-relational database

Foreign names

Nosql=not only SQL

Full Name

Not only

SQL

Category

non-relational database

Application areas

computers, software, databases

3. Analysis of four classified forms of NoSQL database

category	Examples Example	Typical application Scenarios	Data Model	Advantages	Disadvantages
Key value (Key-value) [3]	Tokyo cabinet/tyrant, Redis, Voldemort, Oracle BDB	Content caching, which is used primarily for high-access loads that handle large amounts of data, for some log systems, and so on. [3]	Key-value pairs that point to value and are usually implemented with hash table [3]	Fast Search Speed	Data is unstructured and is usually used only as a string or binary data [3]
Columnstore database [3]	Cassandra, HBase, Riak	Distributed File Systems	To store the same column of data in a clustered type	Find Fast, scalable, and easily distributed extensions	function relative limitation
Document type database [3]	CouchDB, MongoDb	Web applications (similar to Key-value, value is structured, but the database is able to understand the contents of value)	Key-value corresponding key-value pairs, value is structured data	Data structure requirements are not strict, table structure is variable, do not need to be like a relational database need to pre-defined table structure	Query performance is not high, and the lack of uniform query syntax.
Graph (graph) database [3]	Neo4j, Infogrid, Infinite Graph	Social networks, referral systems, and more. Focus on building a relationship map	Graph structure	Using graph structure correlation algorithm. such as shortest path addressing, N-degree relationship lookup, etc.	Many times need to calculate the entire graph to get the information needed, and this structure is not very good for the distributed cluster scheme. [3]

4, the application scenario NoSQL database in the following cases, the comparison is applicable: 1, the data model is relatively simple, 2, the need for more flexible IT systems, 3, the database performance requirements are high, 4, does not require a high degree of data consistency, 5, for a given key, more easily map complex values of the environment.

NoSQL learns a