MySQL Study Notes (1) Basic Introduction

MySQL Study Notes (1) Basic Introduction 1. Comparison with other databases

1.1 Function Comparison

MySQL basically implements most of the ansi SQL 92 standards, and only a small part is not frequently used.

In terms of transaction support, although MySQL's own storage engine is not provided, InnoDB has implemented all the four transaction isolation levels defined in the SQL 92 standard through the third-party plug-in storage engine InnoDB, there may be some differences between each Implementation Method in the implementation process, which is rare in the current commercial database management system.

1.2 usability comparison

MySQL has always adhered to the simple and easy-to-use principle. This feature attracts a large number of beginner database users to choose MySQL.

In terms of installation, the MySQL installation package size is only about 100 MB, which is not an order of magnitude. Installation is much easier than Oracle and other commercial databases.

Compared with the database creation, MySQL only needs a simple create database Command to complete database creation in an instant. Compared with the Oracle database, creating a database is a very huge project.

1.3 Performance Comparison

MySQL has always been proud of its performance .. That is to say, in terms of performance and functionality, the primary consideration for MySQL is performance. MySQL wants to meet 99% of the functional requirements of customers, spend most of the remaining effort on performance, instead of making yourself a database product that is more powerful than any other database.

14. Reliability

From the fact that the most popular websites such as Facebook are using MySQL databases, we can see that MySQL is not inferior to our commercial vendors in terms of stability and reliability. In addition, most of the top 10 large websites in the world are running on MySQL database environments, such as Yahoo and Google.

In general, MySQL Databases have always had three principles: simple, efficient, and reliable.

2 main application scenarios

1. Web website system

MySQL becomes the most favored Database Management System for web site developers because the installation and configuration of MySQL databases are very simple and the maintenance during use is not as complex as that of many large commercial database management systems, and outstanding performance. Another important reason is that MySQL is open-source and can be used for free.

2. log recording system

MySQL database insertion and query performance are very efficient. If the design is good, when using the MyISAM storage engine, the two can do not lock each other to achieve high concurrency performance. Therefore, MySQL is a good choice for systems that require a large number of log inserts and queries. For example, processing user login logs and operation logs is a very suitable application scenario.

3. Data Warehouse System

With the rapid growth of Data Warehouse data size, we need a larger storage space. There are several major solutions: one is to use expensive high-performance hosts to improve computing performance, and use high-end storage devices to improve I/O performance. The results are ideal, but the cost is very high; the second is to copy data to multiple low-cost PC servers that use large-capacity hard disks to improve the overall computing performance and I/O capabilities. The effect is acceptable, the storage space is limited, and the cost is low; third, by splitting data horizontally, multiple low-cost PC servers and local disks are used to store data. Each machine has only one part of all data, solving the problem of data volume, all PC servers work together for parallel computing, which also solves the computing capability problem. By allocating computing tasks of each machine through an intermediate proxy program, the computing performance problem and I/O problems can be solved.
Performance problems and low costs. In the above three solutions, MySQL has great advantages in the implementation of the second and third solutions. Through the simple replication function of MySQL, you can copy data from one host to another, not only in the LAN, but also in the WAN.

4. Embedded System

The biggest restriction on software systems in the embedded environment is that hardware resources are very limited. software systems running in the embedded environment must be lightweight and low-consumption software.