MongoDB

One, what is Bson Bson is a binary form of class JSON, called Binary JSON, which, like JSON, supports embedded document objects and array objects, but Bson has some data types that JSON does not have, such as date and bindata types. Bson can be

01. Welcome to use ueditor! MongoDB supports asynchronous data replication between different services to implement failover (failover, failover, failback) and redundancy (data redundancy). At the same time, only one service node (primary or

Reprint: http://www.cnblogs.com/wilber2013/p/4175825.htmlMongoDB's Official C # driver can be obtained through this link. The link provides the. msi and. zip two ways to get the drive DLL files.Through this article to introduce the basic C # Drive

"interface class definition" [Java] view Plaincopy /** * Project Name: Spidercrawler * File name: Mongodbdao.java * Description: TODO (describe what the file does in a word) */ Package Com.newsTest.dao; Import java.util.ArrayList;

Recently learning MongoDB, in order to deepen the memory, write a writing essay, first start and close MongoDB start1. Start a MongoDB service:Mongod--port XXXX--dbpath/xx/xx--logpath mongo.log--forkThere are four parameters in this command:--port

JSON turn BsonMongoDB is stored in the Bson data format, the JSON string has no way to write directly to MongoDB can convert the JSON string into DBObject or document, and then write to MongoDB1. Convert the JSON character to Com.mongodb.DBObject

To use MongoDB, the natural use of data import and export, I learned a bit.In MONGO study (ii) there are some tools in the Bin directory, this is the use of these tools for data import and export and backup recovery.Note: The following commands are

1. Introduction of ShardsSharding (sharding) is the process of splitting data and spreading it across different machines. MongoDB supports automatic sharding, which allows the database schema to be invisible to the application. For applications, it

Installing MongoDB under Windows is very simple. For a 32-bit operating system, install the 32-bit MongoDB, or 64-bit system to install the 64-bit MongoDB.Here, take 64 bits as an example. The specific steps are:First, download the latest MongoDB or

1. The document's data storage format is Bson, similar to JSON. When MongoDB inserts data, it verifies that there is a "_id" field in the data if it is not automatically generated.There are two ways to insert and save a shell operation. When

The advantages of MongoDB compared to relational databases:① Weak consistency (eventually consistent), to ensure the user's access speed:For example, in a traditional relational database, a count type of operation locks the dataset so that the exact

What is MongoDB?MongoDB is written by the C + + language and is an open source database system based on distributed file storage.In the case of high load, adding more nodes can guarantee the performance of the server.MongoDB is designed to provide

Services run on the line will generate a large number of running and access logs, the log will contain some errors, warnings, and user behavior information, usually the service will be in the form of text log information, so readable, convenient for

We know that MongoDB belongs to a document database, and its stored document types are JSON objects. Because of this feature, we often use MONGODB for data access in node. js. But because node. JS is executed asynchronously, this leads us to not

One, install Method 1, download MongoDB1, the official website to download MongoDB program Https://www.mongodb.org/downloads#production?2. Start MongoDB Service after decompressionDownload and place under the/user/username/app/mongodbTAR-ZXVF

Group of aggregation operationsGrammar:Db.collection.group ({Key:{key1:1,key2:1},cond:{},Reduce:function (Curr,result) {},initial:{},Finalize:function () {}})Key: Group FieldCond: Query criteriaReduce: aggregate functionInitial:

Keep a record, lest you forget. All of them are self-test-used installation process no problem.Linux Common CommandsMV Moving filesmkdir Creating a FolderRM DeleteCP ReplicationNetstat network statusTar decompressionwget downloadRPM Installation

MongoDB backup is actually a basic operation, has been asked recently, it seems that many people are not familiar with the place. To avoid repeating the explanation over and over again, a blog is summed up as a post for later review. Please correct

MongoDB data migration and synchronization of MONGODB data replicationMongoDB requires a minimum of two instances of replication. One is the master node master, which handles client requests and the rest is slave, which is responsible for

The meaning of 'controlfile Checkpointed at scn 'in the trace file after control file dumping The meaning of 'controlfile Checkpointed at scn 'in the trace file after control file dumping Controlfile Checkpointed at scn: 0x0000. 0006c3dc 05/14/2015