比如每个页面结束，数据库连接就关了，下个页面需要重新打开数据库，重新连接，获取数据。这样比起那些可以持久过程，长连接的网站，有什么重大缺点和小优点呢。
回复内容：
比如每个页面结束，数据库连接就关了，下个页面需要重新打开数据库，重新连接，获取数据。这样比起那些可以持久过程，长连接的网站，有什么重大缺点和小优点呢。
首先，不明说是什么数据库，那么就默认为mysql。
然后，web的大部分应用场景适合短链接，而不是长链接。比如你看小说，当小说当前章获取到了后，相当长一段时间用户不会出发新的链接，为何不释放掉该链接让给需要的用户呢？缺点是，反复建立释放链接，也是损耗。
至于长链接，简单的说，就与上面恰恰相反。
其实当具备了sql连接池后，会好很多。
个人愚见，抛砖引玉。
优点是简单.....
每一次连接数据库都涉及很多次 Unix System Call ，总在开闭数据库连接是极大的消耗。
对虚拟主机提供商来说,短连接是友好的.
比如虚拟主机厂商开启了100个Apache或者PHP-FPM工作进程来驱动50个虚拟主机站点,
如果1个站点对应1个到MySQL的持久连接,那么1个工作进程就有可能保持50个持久连接,
100个工作进程就是100*50=5000个持久连接,
而MySQL的最大连接数max_connections默认是151,
这5000个连接对MySQL服务器压力还是非常大的.
而对于只有单个应用的服务器来说,开启持久连接后,
一个PHP-FPM保持一个到MySQL的长连接,实现透明的"连接池",
减少每个请求都重复建立和释放连接的开销,能提升性能.
PHP FastCGI进程管理器PHP-FPM的架构
http://my.oschina.net/eechen/blog/541139
PHP and Python: Different Paradigms ExplainedApr 18, 2025 am 12:26 AMPHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
PHP and Python: A Deep Dive into Their HistoryApr 18, 2025 am 12:25 AMPHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.
Choosing Between PHP and Python: A GuideApr 18, 2025 am 12:24 AMPHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.
PHP and Frameworks: Modernizing the LanguageApr 18, 2025 am 12:14 AMPHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.
PHP's Impact: Web Development and BeyondApr 18, 2025 am 12:10 AMPHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip
How does PHP type hinting work, including scalar types, return types, union types, and nullable types?Apr 17, 2025 am 12:25 AMPHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.
How does PHP handle object cloning (clone keyword) and the __clone magic method?Apr 17, 2025 am 12:24 AMIn PHP, use the clone keyword to create a copy of the object and customize the cloning behavior through the \_\_clone magic method. 1. Use the clone keyword to make a shallow copy, cloning the object's properties but not the object's properties. 2. The \_\_clone method can deeply copy nested objects to avoid shallow copying problems. 3. Pay attention to avoid circular references and performance problems in cloning, and optimize cloning operations to improve efficiency.
PHP vs. Python: Use Cases and ApplicationsApr 17, 2025 am 12:23 AMPHP is suitable for web development and content management systems, and Python is suitable for data science, machine learning and automation scripts. 1.PHP performs well in building fast and scalable websites and applications and is commonly used in CMS such as WordPress. 2. Python has performed outstandingly in the fields of data science and machine learning, with rich libraries such as NumPy and TensorFlow.
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
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.
WebStorm Mac version
Useful JavaScript development tools
SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
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.
Atom editor mac version download
The most popular open source editor
