[Teach a fish to fish] Explain the ACID properties of MySQL

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ACID properties of MySQL:

ACID is a key concept in database management systems (DBMS), which represents the key attributes of transaction processing and ensures the consistency and reliability of database operations. ACID is composed of the following four attributes: Atomicity, Consistency, Isolation, and Durability.

1. Atomicity: Atomicity ensures that all operations in a transaction are either successfully committed or rolled back if they fail. If any operation within a transaction fails, all operations are rolled back to the state before the transaction began, and the database is not left in a partially completed state.

2. Consistency: Consistency ensures that transactions transform the database from one consistent state to another consistent state. This means that transactions must follow defined constraints and rules to maintain data integrity and consistency.

3. Isolation: Isolation ensures that concurrently executing transactions are isolated from each other, and each transaction appears to be logically executed independently. Isolation prevents interference between concurrent transactions and data inconsistencies.

4. Durability: Durability ensures that once a transaction is committed, its results will be permanently stored in the database, even if a system failure or crash occurs. Changes from committed transactions are not lost.

The principles of MySQL are explained in detail:

MySQL implements ACID properties in the following ways:

1. Atomicity: MySQL uses a transaction log to record all operations in a transaction, including writing data, modifying data, deleting data, etc. If a transaction fails, you can use the transaction log to perform a rollback, restoring the database to the state it was in before the transaction began.

2. Consistency: MySQL uses features such as constraints, triggers, and stored procedures to ensure data consistency. By defining appropriate constraints and rules, MySQL can verify the integrity of data during transaction execution.

3. Isolation: MySQL uses a locking mechanism to achieve transaction isolation. When a transaction modifies data, MySQL will lock the related data to prevent other transactions from modifying the same data at the same time, thus ensuring the isolation between transactions.

4. Durability: MySQL uses transaction logs and redo logs to achieve durability. The transaction log records the operations of committed transactions, while the redo log records the changes made to the database. After a database crash or restart, MySQL can use these logs to recover committed transactions and reapply changes, thus guaranteeing durability.

MySQL's underlying architecture flow chart:

The underlying architecture of MySQL involves multiple components and modules. The following is a simplified underlying architecture flow chart of MySQL:

+-------------------------------+
|        Client Application        |
+-------------------------------+
                |
                |
                v
+-------------------------------+
|       MySQL Connector      |
+-------------------------------+
                |
                |
                v
+-------------------------------+
|      MySQL Server (mysqld)    |
|   (Connection, Query Parsing, |
|   Optimization, Execution)   |
+-------------------------------+
                |
                |
                v
+-------------------------------+
|     Storage Engines       |
| (InnoDB, MyISAM, Memory, etc.) |
+-------------------------------+

In the underlying architecture of MySQL, client applications establish connections with the MySQL server through the MySQL connector. The connector is responsible for handling connection requests and authentication. After receiving the query request, the MySQL server performs query parsing, query optimization and execution plan generation. The storage engine is responsible for the actual data storage and retrieval.

MySQL usage scenario explanation:

MySQL is widely used in a variety of different scenarios, including but not limited to the following aspects:

1. Web Applications: MySQL is the database management system of choice for many web applications. It can be used to store and manage user data, content data, member information, etc. Its integration with programming languages ​​​​such as PHP, Python, and Java is very convenient, allowing developers to easily build powerful web applications.

2. Enterprise-level applications: MySQL is suitable for various enterprise-level applications, including customer relationship management systems (CRM), supply chain management systems (SCM), human resource management systems (HRM), etc. MySQL's high performance and scalability make it ideal for handling large amounts of data and high concurrent requests.

3. Data Analysis and Reporting: MySQL is also very useful in data analysis and report generation. It can store and manage large amounts of data and provide powerful query and aggregation functions. Combined with other data analysis tools (such as Tableau, Power BI, etc.), MySQL can help users extract valuable insights from data.

4. Logging and monitoring system: MySQL can be used to store and analyze log data. Many applications and systems generate large amounts of log data, and MySQL can serve as a reliable storage and query engine. It can also be integrated with monitoring systems to help administrators monitor system performance and status in real time.

MySQL code example implementation:

The following is a simple MySQL code example that demonstrates how to create a table, insert data, and query data:

-- 创建表
CREATE TABLE users (
  id INT PRIMARY KEY,
  name VARCHAR(50),
  email VARCHAR(50)
);

-- 插入数据
INSERT INTO users (id, name, email) VALUES
  (1, 'John Doe', '[email protected]'),
  (2, 'Jane Smith', '[email protected]');

-- 查询数据
SELECT * FROM users;

The above code example creates a table named "users" containing three columns: id, name, and email. Then two pieces of data were inserted and all user data was queried using the SELECT statement.

MySQL literature material link:

Here are some links to official documentation and reference materials about MySQL:

1. MySQL official documentation↗ : MySQL official website provides detailed documentation and tutorials, including installation guides, user manuals, developer guides, etc.

2. MySQL High Performance↗ : This book is a classic reference material on MySQL performance optimization and tuning, providing many practical tips and suggestions.

3. MySQL Performance Tuning and Architecture Design↗ : This book covers all aspects of MySQL performance tuning, including query optimization, index design, server configuration, etc.

4. MySQL Cookbook ↗ : This book provides a large number of MySQL examples and solutions for a variety of common database tasks and problems.

Products currently using MySQL:

Many well-known products and organizations use MySQL as their primary database management system. Some products and services currently using MySQL include:

1. WordPress: The popular open source content management system (CMS) WordPress uses MySQL as its default database backend.

2. Facebook: Social networking giant Facebook uses MySQL as one of its main databases and has heavily customized and optimized it.

3. Twitter: Social media platform Twitter used MySQL as its primary database in its early days, although it later switched to a self-developed database system.

4. YouTube: The video sharing platform YouTube has