What cache does mysql use?

mysql cache can be used: 1. Query cache, which is one of the most commonly used caching technologies in MySQL, caching in query statement units; 2. Key cache, which can cache the result set of SQL statement execution. The result set is cached in units; 3. InnoDB buffer pool is a commonly used storage engine in MySQL, with features such as transaction support and row-level locking.

The operating system of this tutorial: Windows 10 system, mysql version 8.0, Dell G3 computer.

MySQL is an open source relational database management system that is widely used in various Web applications and Internet services. For database systems like MySQL, caching is an important performance optimization technology, which can greatly improve the reading speed and response time of the database. MySQL can utilize a variety of caches to improve performance, including query cache, key cache, and InnoDB buffer pool.

Query cache is one of the most commonly used caching technologies in MySQL. When a query is executed, MySQL will first check the query cache to see if there are results identical to the query that have been cached. If so, MySQL can return the results directly from the query cache without having to execute the query again. This can greatly improve the reading speed of the database. However, query caching also has some limitations. For example, when a table is updated, the associated cache is flushed. In addition, the query cache is cached in units of query statements, so only those query statements that are exactly the same can be cached. For slightly different queries, the query cache cannot be used.

Another caching technology is key caching, which can cache the result set of SQL statement execution. Unlike query caching, key caching is cached on a result set basis. When the result set of a query is cached, MySQL can directly return the result set without having to execute the same query again. This can significantly improve database response speed for application scenarios where the same query is executed repeatedly but the results rarely change.

In addition to query cache and key cache, MySQL also provides InnoDB buffer pool. InnoDB is a commonly used storage engine in MySQL, which has features such as transaction support and row-level locking. InnoDB buffer pool is a technology that applies MySQL's caching mechanism to the InnoDB storage engine. It caches table data and index data on disk in memory to speed up read operations on this data. The InnoDB buffer pool can be adjusted according to the system's memory size and can automatically manage the loading and release of cached data.

In addition to the above three caching technologies, MySQL also supports other caching strategies, such as recycle bin caching, binary log caching, etc. These caching technologies can be configured and adjusted according to actual needs.

To sum up, MySQL can use various caches such as query cache, key cache and InnoDB buffer pool to improve the reading speed and response time of the database. These caching technologies can be configured and adjusted according to actual needs to achieve the best performance optimization results. Using appropriate caching strategies, you can significantly improve the performance of the MySQL database, improve the response speed of the application, and thus improve the user experience.

Optimizing cache performance

When using caching technology in MySQL, we need to pay attention to the following aspects to optimize cache performance.

1. Reasonably set the cache capacity and cache elimination strategy. Properly setting the cache size and cache elimination strategy can reduce memory usage and improve MySQL query performance.

2. Avoid cache penetration. Cache penetration is when a large amount of data is queried for data that does not exist in the cache, which causes the query to keep making requests to disk. An effective way is to use Bloom filters to filter data and reduce invalid queries.

3. Avoid cache avalanche. Cache avalanche means that within a certain period of time, a large amount of cached data fails at the same time, causing a large number of requests to fall directly on the database, causing a sudden increase in database pressure and causing server downtime. The solution is generally to use a multi-level caching mechanism to layer the cache, thereby reducing the risk of cache avalanche.

4. Use non-blocking cache operations. In high concurrency situations, using blocking cache operations can impact overall application performance. Therefore, it is recommended to use non-blocking cache operations to improve concurrency performance.

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