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A brief introduction to 1.1 MongoDBIn today's database market, MySQL is undoubtedly a place to occupy. As an open-source relational database , MySQL is widely used in the background of major web sites, and assumes the important role of information

A brief introduction to 1.1 MongoDBIn today's database market, MySQL is undoubtedly a place to occupy. As an open-source relational database , MySQL is widely used in the background of major web sites, and assumes the important role of information

MongoDB's library-level lockMongoDB is currently the most popular NoSQL database, with its natural document-type data structures, flexible data patterns, and easy-to-use horizontal scaling capabilities that have been favored by many developers. But

In the data stored in the database, there is a special key value called the primary key , which is used to uniquely identify a record in the table. In other words, a table cannot have more than one primary key, and the primary key cannot be a null

node. js Connection MongoDBSome introductionMongoDB Https://www.npmjs.com/package/mongodbGitHub Project Address Https://github.com/mongodb/node-mongodb-nativeOwned by the official MongoDB driverDocument http://mongodb.github.io/node-mongodb-native/3.

First, what is MongoDB?A set of high-performance, easy-to-develop document database. He holds data in the form of key-value pairs that can hold most data documents, including strings, arrays, data sequences, pictures, videos, and so on. MongoDB's

1. shardingConcept: In MongoDB There is another cluster, that is, sharding technology, can meet the needs of a large number of MONGODB data volume growth.When MongoDB stores massive amounts of data, a machine may not be enough to store data enough

Transferred from: http://www.cnblogs.com/cswuyg/p/4355948.html1. Count Statistics result errorThis is because the distributed cluster is migrating data, which results in a count result value error and requires the use of aggregate pipeline to obtain

MongoDB is an open source document database that provides high performance, high availability, and auto-scaling. MongoDB is written by the C + + language.Document Database (Documentdatabase):A record is called a document in MongoDB, which is a data

MongoDB is a popular document database, which has features such as easy to use, easy to expand, rich in function and excellent in performance. The MongoDB itself has a highly available and partitioned solution, which is the replica set (Replica set)