1. Documentation
{"Greeting": "Hello,world", "foo": 3} The key/value pairs in the document are ordered, and the following document is a completely different two document from the document above. {"Foo": 3, "greeting": "Hello,world"}2. Usage scenarios
The main goal of MongoDB is to bridge the key/value storage approach (which provides high performance and high scalability) and traditional RDBMS systems (with rich functionality), which combines the advantages of both. According to the official website description, Mongo is suitable for the following scenarios. Website data: Mongo is ideal for real-time inserts, updates and queries, as well as the replication and high scalability required for real-time data storage on the site. Caching: Because of its high performance, Mongo is also suitable as a caching layer for the information infrastructure. After the system restarts, the persistent cache layer built by MONGO can avoid overloading the underlying data sources. Large, low-value data: it can be expensive to store some data using a traditional relational database, and many times programmers often choose traditional files for storage. Highly scalable scenario: The Mongo is ideal for databases consisting of dozens of or hundreds of servers, and the Mongo roadmap already includes built-in support for the MapReduce engine. Storage for objects and JSON data: The Mongo Bson data format is ideal for storing and querying in a document format. The use of MongoDB also has some limitations, for example, it is not suitable for the following places. A highly transactional system: for example, a bank or accounting system. The traditional relational database is still more suitable for applications that require a large number of atomic complex transactions. Traditional Business intelligence applications: BI databases for specific issues produce highly optimized query methods. For such applications, the Data warehouse may be a more appropriate choice. An issue that requires SQL.3. Usage Scenarios
MongoDB (iii):: Small detail issues
