网站标题作弊详解,wordpress for ios,中国建设网官方网站企业,百度关键词排名软件非关系数据库nosql
用来解决特定问题的数据库
特点#xff1a;
1.没有关系模式schema-free/non-relational#xff0c;与关系数据库不同
2.快速处理rapid process#xff0c;数据放在内存中处理
3.distributed process分布式
4.big data
5.easy program
6.open-sour…非关系数据库nosql
用来解决特定问题的数据库
特点
1.没有关系模式schema-free/non-relational与关系数据库不同
2.快速处理rapid process数据放在内存中处理
3.distributed process分布式
4.big data
5.easy program
6.open-source
7.水平式横向拓展性horizontally scalable
类型
1.Document store文档数据库以xml与json的形式存储例子视频网站blog
2.key value/tuple store以个数键值对的形式存储处理速度快
3.
4.Graph Database Management System
5.Multimodel Database Management System
键值数据库Key Value Store
特点简单速度快在内存中
键值要成对形成映射关系
命名空间namespacejava的包package
内存中的in-memory利用了缓存技术把常用的数据放在内存中
redis is an open-source in memory storage, used as a distributed, in-memory key-value database
优势轻量级lightweight快速rapid分布式系统distributed system
劣势查询能力弱weakly retrieve ability缺少数据之间的约束lack of data constraints难解决数据之间的关系hardly handle data relationship
原则扬长避短
1.编程
文档数据库document store
A document - oriented database , or document store , is a computer program and data storage system designed for storing , retrieving and managing document - oriented information , also known as semi - structured data .
半结构化的数据库
优势无需事先定义结构Simple(schema—free)相对关系数据库高效Relatively eficient文档格式Standard document format查询能力强Powerful retrieve ability(semi-structured)分布式Distributed system
劣势没有数据约束Lack of data constraints数据会出现冗余Data redundancy相对键值对数据库低效Relatively ineficient
列族数据库Column families store
A column families database(or wide—column store) is a column-oriented DBMS and therefore a special type of NosQL database. It uses tables, rows, and columns,but unlike a relational database, the names and format of the columns can vary from row to row in the same table
优势为大数据准备suitable for big data processing易于增加新的列easy to add new columns开发工具多tons of development tool检索能力强powerful retrieve ability数据读写快High-speed data I/O
劣势系统复杂complex system数据结构复杂complex data structure难学难用hard to learn/use
