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This article is to share with you what is the MongoDB database, the editor thinks it is very practical, so I share it with you to learn. I hope you can get something after reading this article.

What is MongoDB?

MongoDB is written in C++ language and is an open source database system based on distributed file storage.

In the case of high load, adding more nodes can ensure server performance.

MongoDB aims to provide scalable, high-performance data storage solutions for WEB applications.

MongoDB stores the data as a document, and the data structure consists of key-value (key= > value) pairs. MongoDB documents are similar to JSON objects. Field values can contain other documents, arrays, and document arrays.

Main features

MongoDB provides a document-oriented storage that is relatively simple and easy to operate.

You can set the index of any property in the MongoDB record (such as FirstName= "Ning", Address= "Beijing") to achieve faster sorting.

You can create data mirrors locally or on the network, which makes MongoDB more scalable.

If the load increases (more storage space and stronger processing power are needed), it can be distributed among other nodes in the computer network. This is called fragmentation.

Mongo supports a rich set of query expressions. Query instructions use tags in the form of JSON to easily query objects and arrays embedded in a document.

MongoDb uses the update () command to replace the completed document (data) or some specified data fields.

Map/reduce in Mongodb is mainly used for batch processing and aggregation of data.

Map and Reduce. The Map function calls emit (key,value) to traverse all the records in the collection, passing key and value to the Reduce function for processing.

The Map and Reduce functions are written in Javascript, and you can perform MapReduce operations through db.runCommand or mapreduce commands.

GridFS is a built-in feature in MongoDB that can be used to store a large number of small files.

MongoDB allows scripts to be executed on the server. You can write a function in Javascript and execute it directly on the server, or you can store the definition of the function on the server and call it directly next time.

MongoDB supports a variety of programming languages, such as RUBY,PYTHON,JAVA,C++,PHP,C#.

The above is what the MongoDB database is, and the editor believes that there are some knowledge points that we may see or use in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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