First knowledge of MongoDB

First acquaintance Mongodbby Sun Quan · August 8, 2014 to the new company, did not expect the company useful MONGO database, which let never contact MongoDB I am a little unprepared, can only be a bad supplement. In 2010, NoSQL set off a craze in China, the biggest of which is MongoDB. More and more companies are preparing or already put MongoDB into production environment, many start-up teams also use MongoDB as their preferred database, creating dazzling Internet applications. Description: Features: Powerful, flexible, scalable. It extends the many useful features of a relational database, such as secondary indexes, range queries, and sorting. MongoDB is a very rich feature with built-in support for MapReduce aggregation, which supports geospatial indexing. In addition, MongoDB is committed to being easy to use and accessible. MongoDB has a very friendly data model for developers, and MongoDB's configuration options are easy for managers. Most languages now support MongoDB and are accompanied by powerful drivers. MongoDB also has a JavaScript Shell, which is perfect for JS, and works with MongoDB to do some easy database syntax. Rich data Model: MongoDB is a document-oriented database, not a relational database. As a result, MongoDB has a strong extensibility. The so-called document-oriented data model is a relational line replaced with MongoDB's ' documentation '. A document-oriented data model can embed a document or an array, so a single record can represent a very complex hierarchical relationship. Conforms to the object-oriented development model. MongoDB does not have a pattern: the key of the document is not defined beforehand, nor fixed. Because there is no pattern to change, there is usually no need to migrate data extensively. Instead of putting all the data in a single mold, the application layer can easily add or remove keys. So developers can easily change the data model. Easy to scale: the design of MongoDB considered the problem of expansion, the document-oriented data model allows it to split data between multiple servers, and can balance the data between the cluster and the load, automatically rearrange the document. This allows developers to focus on developing applications, regardless of database load. If you need to increase storage space or improve performance, just add one or more machines, and MongoDB handles the rest. Rich features: index: MONGODB supports secondary indexes, enables multiple quick queries, and provides unique, composite, and geospatial indexing capabilities. Storage JS: Developers do not have to use the storage function, you can access the JS function or value on the server side. Aggregation: MongoDB supports MapReduce and other aggregation tools. Fixed collection: The size of the collection is capped, which is for some data (such asLog) is particularly useful. File storage: MongoDB uses an easy-to-use protocol to store metadata for large files and files. Some common features of relational databases MongoDB does not support, such as joins and complex multi-line things. This architecture is primarily about MongoDB extensibility, because these two features are difficult to implement on a distributed system. Excellent performance: MongoDB's main goal is to have excellent performance, which also greatly affect the design decisions. MongoDB uses the MONGODB transport protocol as the primary tool for interacting with the server (common network protocols require more overhead, such as Http/rest), which dynamically populates the document, allocating data space, and exchanging space for performance. The default storage engine uses a memory-mapped file to turn the memory management work into the operating system. The dynamic query optimizer "remembers" the quickest way to execute queries. MongoDB as much as possible will handle the logic of the server to the client (driver or user application). This design has achieved very good performance. Easy to manage: MongoDB tries to make the server autonomous to simplify the management of the database. In addition to opening the database, there is little else to do. If the server is dead, MongoDB will automatically switch off the backup machine. On a distributed system, the cluster knows only the new nodes, and it automatically integrates and configures them. Reprint please specify the source, the original address: http://www.sundabao.com/%E5%88%9D%E8%AF%86mongodb/

First knowledge of MongoDB