小弟我碰到的MySQL性能优化点
我碰到的MySQL性能优化点 1.在foreach中调用接口(里面执行了查询一条的sql语句) 改进:先将要查询的字段收集到数组里面,然后用in调用一次接口: /** * @brief 式化数据 (收集数组中的字段,最后用in查询) * @param params 原始数组 * @param fields 所需
我碰到的MySQL性能优化点1.在foreach中调用接口(里面执行了查询一条的sql语句) 改进:先将要查询的字段收集到数组里面,然后用in调用一次接口:
/**
* @brief 格式化数据(收集数组中的字段,最后用in查询)
* @param params 原始数组
* @param fields 所需字段
* @return ret 返回数组
* @desc 从数组中获取需要字段,组成新的数组返回,主要用于改变数据库返回数据的格式
*/
public static function getNeedFromListArray($params , $fields) {
$ret = array();
foreach($params as $key => $value) {
$ret[] = $value[$fields];
}
return $ret;
}
2.小集合驱动大集合:先使用子sql语句查询出小的集合,然后再查大的
select s.follow_user_id,p.calledtotallen,p.calling_time
from
(select p.calledtotallen,p.calling_time
from phone_call_log_current p '. $where2 .') p
left join car_sale s on p.sale_id = s.id '.$where1.'
order by p.calling_time desc
limit 0, 10'
3.查询一条数据的时候使用limit 1。(这个就不用例子了)
4.给where,join中的字段增加索引。(平时都是DBA加)
5.用什么数据就查询什么数据
不要图省事用select *
6.建立数据库之前,不要使用NULL(在IOS/Android中出现NULL可能导致崩溃)导致Android/IOS崩溃的null----PHP和Android/IOS数据交互
崩溃了两次之后,为了兼容旧数据,还用了个递归函数,专门来处理这些NULL
7.使用数据为int类型时,不要使用单引号,会降低效率
where id = '123';
加了单引号,成了string,效率更低
8.建立好日志和异常处理非常重要,可以迅速知道,在哪里出现了瓶颈。(尤其是慢查询日志)
这个是所有的模块都要处理的东西。
9.不要使用like字段,如果必须模糊搜索,使用sphinx等,效率和性能会大大提升
like会阻塞掉其他的sql查询

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

MySQL 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.

MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen

Apache connects to a database requires the following steps: Install the database driver. Configure the web.xml file to create a connection pool. Create a JDBC data source and specify the connection settings. Use the JDBC API to access the database from Java code, including getting connections, creating statements, binding parameters, executing queries or updates, and processing results.

MySQL 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.

The process of starting MySQL in Docker consists of the following steps: Pull the MySQL image to create and start the container, set the root user password, and map the port verification connection Create the database and the user grants all permissions to the database

The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.

Laravel is a PHP framework for easy building of web applications. It provides a range of powerful features including: Installation: Install the Laravel CLI globally with Composer and create applications in the project directory. Routing: Define the relationship between the URL and the handler in routes/web.php. View: Create a view in resources/views to render the application's interface. Database Integration: Provides out-of-the-box integration with databases such as MySQL and uses migration to create and modify tables. Model and Controller: The model represents the database entity and the controller processes HTTP requests.

The key to installing MySQL elegantly is to add the official MySQL repository. The specific steps are as follows: Download the MySQL official GPG key to prevent phishing attacks. Add MySQL repository file: rpm -Uvh https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm Update yum repository cache: yum update installation MySQL: yum install mysql-server startup MySQL service: systemctl start mysqld set up booting
