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Jun 07, 2016 pm 03:57 PM

githubstarter

原文首发在github上 MongoNote01.Start MongoDB is an open-source document database that provides high performance, high availability, and automatic scaling. 这是mongo官方给出的定义。定义里的几个关键点体现了mongo的几个突出的优点： document-or

原文首发在github上 MongoNote01.Start

MongoDB is an open-source document database that provides high performance, high availability, and automatic scaling.
这是mongo官方给出的定义。定义里的几个关键点体现了mongo的几个突出的优点：

document-oriented，数据以Bson(Json-style)格式存放在文档中，这个和关系型数据库很大的不同，在mongo中无需按照三范式设计数据库，所以，mongo使用也要比关系型数据库使用起来简单的多。high performance，mongo是C++实现，数据存放简单，不支持jion操作，不支持事务，性能要比sql当然要快。high availability,mongo提供强大的复制功能，当主库挂掉，很方便的使用备份库。automatic scaling,mongo使用sharding进行集群部署，要比SQL方便的多。

但是，也不能只看它的优点，mongo现在也有问题，其中最突出的就是：

不支持事务

总之，相对SQL，mongo的使用比较简单随意，它可以作为SQL之外的有力工具，但是还是不能完全取代成熟的SQL，所以，选择mongo需慎重。

安装Mongo

推荐在Linux64位系统上安装Mongo

1.在官方网站下载压缩包，然后解压到某个目录，如图：

3.运行mongod,如图所示

4.将mongo添加到环境变量中，方便使用命令

5.通过配置文件重新配置mongo的data以及log的属性

在mongo目录下创建mongo.conf文件

dbpath=data/
logpath=log/mogodb.log
logappend=true

此时就可以这样启动mongo了

6.通过mongo命令操作数据库

mongo中的操作命令和SQL中命令有些类似。

通过安装以及简单使用，对mongo有大体的了解。在之后的学习中，通过和SQL对比快速的学习。最好的学习资料，就是官方的：

The MongoDB Manual

也可以下载PDF单文件

The MongoDB Manual.pdf

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