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As the number of website visits increases, MySQL database queries become more and more frequent, and the response speed gradually slows down, resulting in a poor user experience. In order to improve the performance of the website, you can reduce MySQL queries by caching PHP results to optimize the database.
1. Introduction to cache
Cache is a storage medium used to store calculation results for future use. Because the calculated results are saved, the results can be quickly accessed for later use without having to recalculate. In web development, caching can help reduce database access and queries while accessing the cache quickly.
2. Why do you need caching?
In many web applications, the database needs to be queried frequently. Each query takes time, which can slow down your web application accordingly. Without adequate caching, each request requires fetching data from the database, which consumes a lot of time and resources. Therefore, caching is very important to improve the performance of web applications.
3. How to cache data?
Caching can be implemented in PHP through various techniques. The following are several commonly used caching techniques:
File caching is to store the results in a file for future use. When the results need to be accessed, the data can be read from the cache file. File caching has the benefit of being easy to implement, but is only suitable for small web applications.
Memcached is a special key-value storage system used for caching in applications. When using Memcached, results are stored in memory for faster access. Memcached can be used on a single server, but it can also be used on multiple servers to support higher request volumes.
Redis is an open source key-value storage system that can be used for data caching, message queuing and ranking. Unlike Memcached, Redis can also persist data to disk so that it can be restored in the event of a power outage. Redis is suitable for large web applications because it is very flexible and can scale the server as needed.
4. How to use caching to shorten MySQL queries?
The following are several ways to use caching to reduce MySQL queries:
When the data needs to be used and updated frequently, use Caching can greatly reduce query times. For example, if a user views an article, we can store it in cache for faster access in the future. In addition, if the article is updated, we need to modify the cache so that the next time the cache is read, the latest content is obtained.
The cache is not permanently stored in memory. When the data in the cache is updated frequently, we can set the cache expiration time so that the cache is regenerated regularly. In addition, we can also develop different caching strategies based on the frequency and importance of data reading and writing. For example, alternatively frequently accessed data can be set up as a persistent cache, while less frequently used data can be set up as a short-term cache.
MySQL queries can use the optimizer to get results from the database as quickly as possible. The optimizer can use various techniques such as indexing, caching, and aggregation to ensure the most efficient query. By using the query cache, you can greatly reduce MySQL queries and reduce access to the MySQL database by storing the results in the cache.
Summary
Caching is an important method to improve the performance of web applications and can be used to reduce MySQL queries and speed up web page response times. By using file caching, Memcached, or Redis, you can significantly reduce MySQL queries and improve the performance of your web applications. When using cache, you need to develop a cache strategy so that cached data can be updated and invalidated in a timely manner.
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