A MongoDB Introduction

I. Definition

high-performance, open source, modeless document-type NoSQL database

Note: 1, the file storage format is Bson (a JSON extension, 2-in-system expression, high efficiency)

2. Free mode: No table structure

3, support dynamic query: Conditional query, paging query and statistical inquiry

4, support full index: have general index and full index

5. Support for replication and failure recovery

Example: {"Hello": "World"}---------->{"\x16\x00\x00\x00\x02hello\xoo", "\x06\x00\x00\x00world\x00\x00"}

6, the use of efficient binary data storage, including large objects (video)

7, automatic processing of debris to support the scalability of the computational hierarchy

8, Support Java, Ruby, python,c++ and other languages

9. Support JavaScript

Second, advantages

1. Fast query speed

2, high concurrency, about 20,000; Oracle Enterprise Edition concurrency number, single node is 5,000

3, high capacity of more than 10TB

Third, MongoDB applicable scene

1, the website data------> Inserts the update in real time

2, Cache--------"such as Redis

3, large size, low value of data

4, highly scalable scene--------"hundreds of server clusters

5, for objects and JSON data storage

such as: SourceForge-----------------> Open Source Hosting website

Iv. restrictions on the use of MongoDB

2.5G data storage is not supported on 1, 32-bit operating systems

2. Single File Size "=16m

3. Systems that do not support high things: such as banking systems or accounting systems, require a large number of atomic complex things

4, the traditional business intelligence application

v. Comparison with relational databases

1, Mongodb

Database, collection, document (one row of data in a table), Key (table field), no primary foreign key, flexible extension extremely high

2. Relational database (Oracle, MySQL)

databases, two-dimensional tables, a record (one row of data in a table), Columns (table fields), PK and FK (primary foreign key), flexibility spread difference

vi. installation of MongoDB

1, Download: www.mongodb.org

2, decompression download of the compressed package, renamed to MONGO

3, local disk to create a MongoDB folder for storing MONGO data files

4, start the service: Mongod.exe

Start client: Mongo.exe

Note: server-side for data storage, client access to data

5, set the statement:

D:\mongo\bin\mongod--dbpath=d:\db--logpath=f:\mongo\logs\mongodb.log--port=27017

Note: DBPath represents the MongoDB's data store address, LogPath represents the MongoDB's log file address, and port represents the number of ports visited.

Seven, mongo command parameter description

1, dbpath: Data file storage path, used to prevent the use of a power to run multiple Mongof.lock also saved in this directory

2, LogPath: Directory of log files

3, Logappend: Log file with the Append mode, the default is direct coverage mode

4, BIND_IP: External services of the binding IP, generally set to null and binding on all available IP on this machine

5, Port: External service port, Web management port on the basis of this port minus 1000

6, Fork:linux under the use, indicating the daemon form of the operation of the service

7, Journal: Open the Log function, used to restore the log

8, Syncdelay: The system synchronized Refresh Disk Time (default is 60s), and Redis similar

9, Directoryperdb: Each db stored in a separate directory, easy to maintain

10, Maxconns: Maximum number of connections

11, Repairpath: Restore the data mechanism, not commonly used. If to open journal, abnormal down machine after reboot must perform require operation