MONGDB Entry Series-What is MONGDB?

# Introduction
# # What's a mongdb?
1.MongDB is written in the C + + language, is a distributed storage-based open source database system, in the case of high nodes, add more nodes, can guarantee server performance
* * Performance is very high, read and write can reach 20,000 times per second * *
2.MongDB is designed to provide scalable, high-performance data storage solutions for Web applications
3.MongDB stores data as a document, data structures consist of key-value pairs, and mongdb documents are similar to JSON objects. Field values can contain other documents, arrays, and document arrays
# Two History
1. October 2007, MongoDB was developed by 10gen team. Launched in February 2009.

2, May 23, 2012, MongoDB2.1 Development Branch released! This version incorporates a new architecture with many enhancements.

3, June 06, 2012, MongoDB 2.0.6 released, distributed document database.

4, April 23, 2013, MongoDB 2.4.3 released, this version includes some performance optimizations, enhancements, and bug fixes.

5, August 20, 2013, MongoDB 2.4.6 released, is currently the latest stable version.

.................
# # three main features

1, you can set the index of any property in the MongoDB record (for example: Firstname= "Sameer", address= "8 Gandhi Road") for faster sorting.
2. You can create data mirroring either locally or on the network, which makes MongoDB more extensible.
3. If the load increases (requiring more storage space and greater processing power), it can be distributed across other nodes in the computer network this is called sharding.
The 4.Mongo supports rich query expressions. Query directives use a JSON-style tag to easily query objects and arrays embedded in the document.
5.MongoDb Use the update () command to implement a replacement of the completed document (data) or some specified data fields.
The map/reduce in 6.Mongodb is primarily used for batch processing and aggregation of data.
7.Map and reduce. The map function calls emit (Key,value) to traverse all records in the collection, passing key and value to the reduce function for processing.
The 8.MAP function and the reduce function are written in JavaScript and can be executed with the Db.runcommand or MapReduce command.
9.GridFS is a built-in feature in MongoDB that can be used to store a large number of small files.
MongoDB allows you to execute scripts on the server, write a function in JavaScript, execute directly on the server, or store the definition of the function on the server, next time you call it directly.
The 10.MongoDB supports a variety of programming languages: ruby,python,java,c++,php,c# and many other languages.
11.MongoDB installation is simple.

MONGDB Entry Series-What is MONGDB?