MongoDB

Manual Pre-sharding:Purpose: Manual pre-sharding is intended to prevent future chunk movement and reduce IO.Sh.shardcollection ("Shop.users", {"UserId": 1})for (var i=1; iInsert data for validation:for (var i=1; iFrom the above, the data is evenly

1. Master-slave replication is a simple database synchronous backup of the cluster technology1.1 In the database cluster Chinese medicine clear know who is the primary server, the primary server only one, from the server can be more than one1.2 From

The NoSQL type of database Redis was contacted during the previous period, and was used as a cache server. So from this blog start learning there is a very well-known NoSQL database: MongoDb. It's just not being used in development right now. Step

1. Close the databaseCTRL + C;or Db.shutdownserver ()2. Import and ExportMongoexport-d indicates which library to use-C indicates the table to be exported-O indicates the file name to export-csv specifying the exported CSV format-Q Filtering Export--

Role Specific Description:READ: Allows the user to read the specified databaseReadWrite: Allows the user to read and write to the specified databaseDbAdmin: Allows the user to perform administrative functions in the specified database, such as index

Remove () methodThe Remove () method in MongoDB is used to remove a document from the collection. The Remove () method accepts two parameters. One is a delete condition, the second is a flag: Justone.Criteria-(optional) The collection that meets the

Mongo command: Show Databases/dbs; Use test; Show Tables/collections; Db.help () Db.createcollection (' user ') Db.user.insert ({name: ' Sky ', age:22}) Db.user.insert ({_id:2, Name: ' Allen ', age:23})

MongoDB's design pattern strategyReading notes1. Query command Classification modeThe responsibilities in the replica set are detached to different nodes. The most basic first-class node may also occupy the top position, and it only needs to store

Polymerization aggregate Aggregation (aggregate) is primarily used to calculate data, similar to sum (), AVG () in SQL Grammar db.集合名称.aggregate([{管道:{表达式}}])Pipeline Pipelines are typically used in UNIX and Linux to input

First step to download MongoDBHttp://www.mongodb.org/downloadsStep TwoExtracted to the D:\mongodb\ directory, for the convenience of the command line, you can add the D:\mongodb\bin to the system environment variable path.Step ThreeCreate D:\mongodb\

You expect a higher write loadby default, compared to transaction security, MongoDB pay more attention to the high insertion speed. If you need to load a lot of low-value business data, MongoDB will be a good fit for your use case. But you must

1. Download and installwget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-3.0.6.tgzTar zxf mongodb-linux-x86_64-3.0.6.tgzMV Mongodb-linux-x86_64-3.0.6/usr/local/mongodb2. Create a data directory that must be created or fail to

The three parameters of the MongoDB Update method are Upsert, which is a Boolean type and the default is False. When it is true, the Update method first finds the record that matches the first parameter, and when it is updated with the second

1. Why study?project needs, the company needs to dig up valuable information from the previous log records and purchase information, the data volume of large structure complex;The requirements of the project decide to solve the problems of

Toss two days, the former leader left the mess, the day before yesterday suddenly hung up, the whole company I will Linux, Grandma's, Long story.Below is a record of how to install MongoDB, the front is copied from the Novice tutorial1. Download -

MongoDB Basic use after the successful start MongoDB, and then open a command line window input MONGO, you can do some operations of the database. Enter help to see the Basic Operations Command: Show DBS: Show list of databases show collections:

MongoDB is a non-relational database (NOSQL) that implements object-oriented thinking (Oo thought), and each record in MONGO DB is a document object. The biggest advantage of Mongo DB is that all data persistence requires no developers to write SQL

1. Download the compressed packageWget-c http://downloads.mongodb.org/linux/mongodb-linux-i686-2.4.9.tgz2. UnzipTAR-XZVF mongodb-linux-i686-2.4.9.tgz3. Move the extracted folder to/usr/local/mongodbMV Mongodb-linux-i686-2.4.9/usr/local/mongodb4.

first, the basic concept1: Document is the basic unit of data in MongoDB, very similar to line 2 in a relational database management system: A collection (collection) can be seen as a dynamic Schema) An instance of table 3:mongodb can have multiple

D:\mongodb>Mongod--DBPath D:\mongodb\data--logpath D :\MongoDB \log\mongodb. Log -- logappend  --serviceName  mongodb-- Auth -- install Workaround:This problem usually occurs because of a problem with the path. 1) Please note that all your