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1, Database operation 1) Select and create database syntax: use database name The rule of the use command is to switch if the corresponding database exists, and create if it does not exist 2) Deletion of database db.dropDatabase() 3) View databases with permissions show dbs or show databases Note: when you use the use com ...

mongoDb replica set It mainly provides two functions 1. When data is written to the Primary node, copy the data to another replica node 2. When the primary node fails, a new replacement node is automatically selected Typical replica set structure A typical replication set consists of three or more nodes with voting rights. ...

As usual, the figure above first. In the last NOSQL article, a big man said that he would learn all the databases of the first figure. Today, he specially posted only one small figure. One is enough! preface Mongo does not mean Mango, but comes from the word Humongous. MongoDB is a NoSQL database based on distributed file storage. W ...

Environmental Science OS: Ubuntu20.04 MongoDB: v5.0.2 Introduction to MongoDB MongoDB is an open source document database that provides high performance, high availability, and automatic scaling to provide scalable high performance data storage solutions for WEB applications. MongoDB is a product between relational and non-relational datab ...

CentOS 7.9 MongoDB installation and use 1, Software download and installation Note: CentOS versions include RedHat / CentOS 7.0 and RedHat / CentOS 7.2 s390x. It is recommended to download software installation packages consistent with the CPU architecture of the operating system to ensure compatibility and high performance. Enter arch ...

MongoDB Map Reduce MAP REDUCE is a computing model, which simply means that a large number of work (data) are decomposed (MAP) and executed, and then the results are combined into the final result (REDUCE). The map reduce provided by MongoDB is very flexible and practical for large-scale data analysis. MapReduce command The following is t ...

1: jar packages to be referenced: <!-- mongodb Link package --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-mongodb</artifactId> <version>2.3.4.RELEASE</version> </dependency> 2: This ...

This article describes how to save a picture file to MongoDB using the GridFS API.The GridFS API can also save other binary files, such as video and music files. 1. Save pictures The following code uses the photo namespace, and the new filename saves the picture to MongoDB. String newFileName = "mkyong-java-image"; File imageFile = new ...

1, Mongodb cluster (no SQL Library) cluster construction 1. For the topology of Mongo cluster, let's have a brief understanding2. Install mongodb to node1, 2, and 3 nodes (the following operations should be performed on node1, 2, and 3 nodes, xshell is recommended) (1) Configure mongo's yum source Com ...

Contents of this article The foregoing install linux Installation docker container deployment Windows setup use GUI viewer Differences between mongoDB and relational database mongoDB basic syntax pymongo module usage The foregoing mongoDB should be a non relational database according to the ...