Applicable and inapplicable scenarios of mongodb series

MongoDB Is an open source distributed architecture NoSQL Database management system . In front of NoSQL and SQL contrast I am learning , We know NoSQL Database system and traditional RDBMS Differences and advantages of

1、MongoDB advantage

You can simply list MongoDB Some obvious main advantages

• Speed ：MongoDB Much faster than a normal relational database , As a document oriented NoSQL database ,MongoDB You can make it easy and fast to access documents by indexing
• Fragmentation ：MongoDB Another advantage is that it allows users to store large amounts of data , It distributes data to multiple servers by means of sharding .
• flexibility ： because MongoDB Is an unstructured database system , And multiple data types , So it doesn't need to be like relational data , Special table structure design , Storing data is more flexible
• Distributed ：MongoDB The database supports distributed by default , In band distributed solutions

2、MongoDB limitations

• Connection is not supported ： Unlike rational databases that support connections ,MongoDB I won't support it . Although you can add connectivity by manually encoding , But it may be slow to execute and affect performance .
• Data size is limited ：MongoDB The maximum number of documents allowed is 16MB
• Cannot nest infinitely ：MongoDB The data format of is BSON Of , But it does not support infinite nesting , Users cannot exceed 100 Level document nesting
• High memory ：MongoDB The key name of each value pair is stored . It is also affected by data redundancy , Because it lacks the function of connection . This leads to high memory usage .
• Complex business queries are not supported ：MySQL These types of databases can perform complex business queries such as table joins ,MongoDB It's a document database , Therefore, associated tables are not supported (Collection) Inquire about

3、 Applicable scenario

Summed up MongoDB After some obvious features , We can know MongoDB Some applicable scenarios of .

stay MongoDB The official website also lists MongoDB The applicable scenarios of ：

• 1） Website real time data :MongoDB Perfect for real-time insertion , Update and query , It also has the replication and storage functions required for the real-time data storage of the website
  Highly scalable .
• 2） Data caching : Because of the high performance ,MongoDB It is also suitable as a caching layer for information infrastructure . After system restart , from MongoDB
  The built persistence cache layer prevents the underlying data source from being overloaded .
• 3） Big size 、 Low value data storage : Using traditional relational database to store some data may be more expensive , Before that , very
  Programmers often choose traditional files for storage .
• 4） Highly scalable scenario :MongoDB It is very suitable for a database composed of dozens or hundreds of servers .MongoDB Already included in the roadmap for
  Yes MapReduce Built in engine support .
• 5） Object or JSON data storage :MongoDB Of BSON The data format is very suitable for the storage and query of document format .

4、 Not applicable to the scene

• 1） Highly transactional systems : Financial systems such as banking or accounting . The traditional relational database is still more suitable for applications that need a large number of atomic complex transactions .
• 2） Traditional business intelligence applications : Specific to a specific problem BI The database will generate highly optimized queries for . For such applications , Relational may be a more appropriate choice .

therefore , For the need for complexity SQL Query questions .MongoDB It's not very suitable , In terms of technical options, you need to select the appropriate database according to the business scenario and the actual situation of the company , Relational databases and NoSQL Each database has its advantages and disadvantages , The database should be reasonably selected according to the actual scenario

5、 Reference material

• MongoDB Application scenarios ：https://hevodata.com/learn/mongodb-use-case/
• MongoDB Official website address ：https://www.mongodb.com/
• MongoDB Official English documents ：https://docs.mongodb.com/manual/
• MongoDB Download address of each platform ：https://www.mongodb.com/download-center#community