关于分表的问题
请教高手以下几个问题
1.将超过100万的表就进行分表.
2.如果B数据表拆分100万的表有十个,那么A表中的ID在B表有5条数据，保存在B数据表拆分的10个表中（问题出来了，在读取数据时，不可能去读去B表中所有的表，这5条数据可能放在拆分的第5与第6个表中，如果这样我们只里要读取B表的第5个表与第6个表就行了。前提是我们根本不知道数据在那）。
回复讨论(解决方案)
关注下，最多碰过200W的数据，加索引后很见效，想了解下经过优化的单表数据上限最好是多少条
如果是普通的查询语句几百万条加了索引查询速度没问题的，但连表或子查询就比较慢了
横向分表 需要知道目标ID的位置，不然会起反作用效率更慢。
看看能不能按你的外键算法进行分表
分表是有条件的，并非简单的按记录顺序切断
比如你的 A 和 B 是按 id 关联的，那么 B 就要按 A.id 拆分
这样在已知 A.id 的情况下，按拆分规则就可推算出相关的记录会出现在哪些 Bn 中
如果你的表间存在多对多的关系，那么分表就没有意义了
此时应使用过渡表保存关联关系，查询时要分两步走，而不是一次关联所有表
由于过渡表一般只有2列，虽然记录数很多，但一次性加载到内存的可能性很大（就算是需要多次加载，但每次可加载的记录数也很多）
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
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Alipay PHP SDK transfer error: How to solve the problem of 'Cannot declare class SignData'?
Apr 01, 2025 am 07:21 AM
Alipay PHP...
How does session hijacking work and how can you mitigate it in PHP?
Apr 06, 2025 am 12:02 AM
Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
Describe the SOLID principles and how they apply to PHP development.
Apr 03, 2025 am 12:04 AM
The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.
How to debug CLI mode in PHPStorm?
Apr 01, 2025 pm 02:57 PM
How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...
How to automatically set permissions of unixsocket after system restart?
Mar 31, 2025 pm 11:54 PM
How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
How to send a POST request containing JSON data using PHP's cURL library?
Apr 01, 2025 pm 03:12 PM
Sending JSON data using PHP's cURL library In PHP development, it is often necessary to interact with external APIs. One of the common ways is to use cURL library to send POST�...
