digitalocean mongodb

Label:One. MongoDB CREATE database: Use commandMongoDB use database_name is used to create a database. The command creates a new database and returns the existing database if it does not exist.Grammar:The basic syntax for the use DATABASE statement is as follows: Use database_nameExample:If you want to create a database name mydb, then the use database statement is as follows: > Usemydb switched to DB mydb To check the currently selected database usi

Tags: c4c com own version resources background massive data LSE OCAWhat is a shard?High data volume and throughput of the database application will be more pressure on the performance of the single machine, large query volume will be a single CPU exhausted, large amount of data on the single-machine storage pressure, and eventually will exhaust the system's memory and transfer the pressure to disk IO.MongoDB shards are a way to store data using multiple servers to support huge data stores and ma

MongoDB learning-Continuous updates and continuous mongodb Learning Refer to the MongoDB authoritative guide for more information and updates in this article. Advantages of MongoDB MongoDB has rich data models and is a document-oriented database. It i

Clever Use of Mongodb for geographic space query, mongodb geographical space MongoDB is a distributed file storage-based database. Written in C ++. It is designed to provide scalable, high-performance data storage solutions for WEB applications.In mobile development, positioning functions are often used, such as Meituan, ELE. Me, and cat-eye movies, then find so

After reading the introduction, we only know that the Mongodb data is in the file using json. But I still don't understand. who can help me compare what the relational databases correspond to in Mongodb. I know it is not a kind of thing, but if it is all about data storage, it can explain how mysql is stored and how Mongodb is made. Thank you. Mysqljsonmongodb da

center, and machine model. If I retrieve 12 million pieces of data at a time, it is not said that mysql takes time to query data under the default configuration.2 sThe above, and it takes nearly to create such a large array in ruby.10 sNot to mention making more judgments and statistical logic in the future. I can't imagine what would happen if I had to analyze data for a week or a month. So I came up with"Should I try mongodb"This time, I am on the

[Spring Data MongoDB] learning notes -- MapReduce, mongodb -- mapreduce Mongodb MapReduce mainly includes two methods: map and reduce. For example, assume that the following three records exist: { "_id" : ObjectId("4e5ff893c0277826074ec533"), "x" : [ "a", "b" ] }{ "_id" : ObjectId("4e5ff893c0277826074ec534"), "x" : [ "b", "c" ] }{ "_id" : ObjectId("4e5ff893c02778

In fact, the indexes in MongoDB are similar to relational databases. They are designed to improve the efficiency of query and sorting, and the Implementation Principles are basically the same. The keys (fields) in the set can be common data types or subdocuments. MongoDB can create indexes on various types of keys. The following describes how to create, query, and maintain various types of indexes. I. Creat

Mongodb DBObject supports saving multi-dimensional arrays. When adding elements, use the "$ push" operator and "$ pull" When deleting elements ". However, the problem arises when updating. mongodb first supports "$" to locate an element in the array, for example:View plain > T. find () {"_ Id": ObjectId ("4b97e62bf1d8c7152c9ccb74"), "title": "ABC ", "Comments": [{"by": "Joe", "votes": 3 },{ "by": "Jane"

table to store one-to-many/many-to-many relationships. Although I am not sure whether it can be done, I have not considered this in depth. If you think of a good design, please leave a message to discuss with me Let's rethink the nature of the log module: 1. A large amount of data 2. Only a large amount of data (not associated with other modules, pure data) This scenario reminds me of nosql. Here, we use MongoDB for implementation. For more informat

MongoDB step by step (2) mongodb compared with T-SQL, mongodbt-SQL SQL Terms/Concepts MongoDB Terms/Concepts Database Database Table Collection) Row Document) Column Key) Value Value) Index Index Table joins Embedded documents and linking Primary key Pri

Basic operations of mongodb and basic operations of mongodb Install mongodb in http://blog.csdn.net/u011575570/article/details/47791135Including linux and WindowsThe following are some basic operations:/Usr/local/mongodb/bin/mongo # Start mongodbMongoDB shell version: 2.2.6Connecting to: test Show dbs; # view Datab

Official MongoDB documentation translation series: Official mongodb documentationIntroduction This document provides a method for writing data into multiple documents using two-phase commit to process multi-document updates or "Multi-document transactions ". On this basis, you can expand and implement functions similar to data rollback.Background In MongoDB datab

SQL terms/concepts MongoDB terms/concepts Database Database Table Collection (Collection) Row Document (documentation) Column Key (Keys) Value Value (values) Index Index Table joins Embedded documents and linking Primary key Primary key Specify any unique column or column combination

The indexes in MongoDB are similar to relational databases, all in order to improve the efficiency of query and sorting, and the principle of implementation is basically consistent. Because the key (field) in the collection can be a normal data type, it can also be a subdocument. MongoDB can create indexes on various types of keys. The following sections explain the creation of various types of indexes, que

One, MongoDB command说明：Mongodb命令是区分大小写的，使用的命名规则是驼峰命名法。 对于database和collection无需主动创建，在插入数据时，如果database和collection不存在则会自动创建。Common commandsHelp commandWith this command you can see some of the most basic commands,Use commandFor example, command "Use Demodb", create demodb without worrying that DEMODB will not be created, and automatically create a database collection when using the use DEMODB command to creat