0x00 Mysql数据库常用存储引擎
Mysql数据库是一款开源的数据库，支持多种存储引擎的选择，比如目前最常用的存储引擎有：MyISAM，InnoDB，Memory等。
MyISAM存储引擎
MyISAM是Mysql的默认存储引擎，它支持B-tree/FullText/R-tree索引类型，并且MyISAM的锁级别是表锁，表锁的开销小，加锁快；锁粒度大，发生锁冲突的概率较高，并发度低；表锁适合查询。MyISAM引擎不支持事务性，也不支持外键。
InnoDB存储引擎
InnoDB存储引擎最大的亮点就是支持事务性，支持回滚。它支持Hash/B-tree索引类型。InnoDB的锁级别是行锁，行锁在锁定上带来的消耗大于表锁，但是在系统并发访问量较高时，InnoDB整体性能远高于MyISAM。InnoDB的索引不仅缓存索引本身，也缓存数据，所以InnoDB需要更大的内存。
Memory存储引擎
Memory存储引擎是一个内存级的存储引擎，它将所有数据都存储在内存中，所以它能够存储的数据量是比较小的。而因为内存的特性，Memory存储引擎对于数据的一致性支持教差。Memory的锁级别和MyISAM一样，是表锁；并且不支持事务性。
0x01 如何选择合适的存储引擎
采用MyISAM引擎
R/W > 100 : 1并且Update较少 (R/W:读写比) 并发不高，不需要支持事务 表数据量小 需要进行全文搜索采用InnoDB引擎
R/W比较小，频繁更新大字段 表数据量超过千万，高并发 安全性和可用性要求高采用Memory引擎
有足够的内存 对数据一致性要求不高，如session/在线人数等 需要定期归档的数据0x02 结语
数据库的选择，数据库存储引擎的选择，以及数据库的优化，就像是一门艺术，它没有好与坏之分，只有适合与不适合。一个项目需要考虑的因素很多，如何去权衡几个因素之间的权重，如何找到一个最优解，真的需要长时间的经验积累，数据库的学习之路漫漫，坚持，再坚持！
MySQL: An Introduction to the World's Most Popular DatabaseApr 12, 2025 am 12:18 AMMySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.
The Importance of MySQL: Data Storage and ManagementApr 12, 2025 am 12:18 AMMySQL is an open source relational database management system suitable for data storage, management, query and security. 1. It supports a variety of operating systems and is widely used in Web applications and other fields. 2. Through the client-server architecture and different storage engines, MySQL processes data efficiently. 3. Basic usage includes creating databases and tables, inserting, querying and updating data. 4. Advanced usage involves complex queries and stored procedures. 5. Common errors can be debugged through the EXPLAIN statement. 6. Performance optimization includes the rational use of indexes and optimized query statements.
Why Use MySQL? Benefits and AdvantagesApr 12, 2025 am 12:17 AMMySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.
Describe InnoDB locking mechanisms (shared locks, exclusive locks, intention locks, record locks, gap locks, next-key locks).Apr 12, 2025 am 12:16 AMInnoDB's lock mechanisms include shared locks, exclusive locks, intention locks, record locks, gap locks and next key locks. 1. Shared lock allows transactions to read data without preventing other transactions from reading. 2. Exclusive lock prevents other transactions from reading and modifying data. 3. Intention lock optimizes lock efficiency. 4. Record lock lock index record. 5. Gap lock locks index recording gap. 6. The next key lock is a combination of record lock and gap lock to ensure data consistency.
What are common causes of poor MySQL query performance?Apr 12, 2025 am 12:11 AMThe main reasons for poor MySQL query performance include not using indexes, wrong execution plan selection by the query optimizer, unreasonable table design, excessive data volume and lock competition. 1. No index causes slow querying, and adding indexes can significantly improve performance. 2. Use the EXPLAIN command to analyze the query plan and find out the optimizer error. 3. Reconstructing the table structure and optimizing JOIN conditions can improve table design problems. 4. When the data volume is large, partitioning and table division strategies are adopted. 5. In a high concurrency environment, optimizing transactions and locking strategies can reduce lock competition.
When should you use a composite index versus multiple single-column indexes?Apr 11, 2025 am 12:06 AMIn database optimization, indexing strategies should be selected according to query requirements: 1. When the query involves multiple columns and the order of conditions is fixed, use composite indexes; 2. When the query involves multiple columns but the order of conditions is not fixed, use multiple single-column indexes. Composite indexes are suitable for optimizing multi-column queries, while single-column indexes are suitable for single-column queries.
How to identify and optimize slow queries in MySQL? (slow query log, performance_schema)Apr 10, 2025 am 09:36 AMTo optimize MySQL slow query, slowquerylog and performance_schema need to be used: 1. Enable slowquerylog and set thresholds to record slow query; 2. Use performance_schema to analyze query execution details, find out performance bottlenecks and optimize.
MySQL and SQL: Essential Skills for DevelopersApr 10, 2025 am 09:30 AMMySQL and SQL are essential skills for developers. 1.MySQL is an open source relational database management system, and SQL is the standard language used to manage and operate databases. 2.MySQL supports multiple storage engines through efficient data storage and retrieval functions, and SQL completes complex data operations through simple statements. 3. Examples of usage include basic queries and advanced queries, such as filtering and sorting by condition. 4. Common errors include syntax errors and performance issues, which can be optimized by checking SQL statements and using EXPLAIN commands. 5. Performance optimization techniques include using indexes, avoiding full table scanning, optimizing JOIN operations and improving code readability.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.
Dreamweaver Mac version
Visual web development tools
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
