Primary relational database (SQL) vs. non-relational database (NOSQL)

I. Relational database ( SQL):

Mysql,Oracle

features : There is a relationship between data and data , between Tables and fields , between tables and tables

For example : Department table 001 section, Employee table 001

User table , user name , password

Classification Table and commodity tables , one -to-many relationships.

Advantages :There is a relationship between ① data, it is very convenient to make and delete data.

② relational databases have transactional operations. ensure the integrity of your data

Disadvantages :1, because of the relationship between data and data, the relationship is guaranteed by the underlying large number of algorithms

A lot of algorithms will slow down the system.

A large number of algorithms consume system resources

2, the huge amount of data additions and deletions will appear powerless .

It's probably down.

3, large Data Environment to maintain /expand the data Sheet , will become powerless

Update product Set cname = ' mobile phone digital ';// Modify all data

Put the Product table in the CNAME field, by varchar (100), Char

Ideal for handling general-scale data and safe .

two. Non-relational database ( NOSQL):

in order to deal with large amounts of data , the relationship between relational database needs to be removed.

the initial design of non-relational database is to replace of the relational database

Redis

Advantages :1, large amount of data deletion and modification, very easy to deal with

2, the maintenance of massive data is very easy .

Disadvantages :1. There is no relationship between data and data, so you cannot glance at it

2, non-relational database , no relationship , no strong transaction to ensure the integrity and security of data

Ideal for handling massive amounts of data and efficiency . Not necessarily safe .

Olympic Athletes Medal total

relational database + non-relational database = = = ="Project"

Important Data massive operational data, not important

Primary relational database (SQL) vs. non-relational database (NOSQL)