Introduction to Databases

1. What is a database

Databases: Database, the medium in which data is stored and processed efficiently (there are two main types of media: Disk and memory).

2, the classification of the database

Database based on the different storage media, can be divided into two categories: relational database (SQL) and non-relational database (Nosql:not only SQL, not relational database called non-relational database)

3. What are the products in different database camps?

relational database

Large: ORACLE,DB2

Medium: Sql-server,my-sql, etc.

Small: Access, etc.

Non-relational database: Memcached,mongodb,redis (synchronous technology) and so on.

4. Differences between the two database camps

Relational database: Secure (it is not possible to lose data on disk), easy to understand, waste space (two-dimensional table storage)

Non-relational database: High efficiency, unsafe (lost power loss)

Introduction to Databases