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MySQL Performance Tuning Guide

for optimal database efficiency

Structured Search Language (SQL) is a powerful tool for managing data in relational databases, including popular systems such as MySQL, Postgres, Oracle, SQL Server and others.

By using SQL statements, developers can easily perform various database management operations, such as creating, updating and deleting data.

As data volumes and technology complexity increase, optimizing MySQL databases is crucial to deliver a seamless end-user experience and reduce infrastructure costs.

In this blog, we will discuss MySQL performance tuning tools that can help database professionals identify bottlenecks, review execution query plans and eliminate guesswork.


Tips for improving MySQL performance

Optimizar el rendimiento de una base de datos y la ejecución de consultas MySQL es crucial para maximizar el rendimiento del sistema. Sin embargo, el ajuste de SQL puede ser complejo y llevar mucho tiempo a los desarrolladores, ya que requiere conocimientos técnicos para comprender y escribir diferentes planes de ejecución.

Con los retos que plantean los enfoques de ajuste inciertos para sentencias SQL únicas, dominar el ajuste del funcionamiento de las bases de datos es esencial en los entornos actuales basados en datos.

Advantages of MySQL performance optimization

These are the benefits of MySQL performance tuning:

Cost optimization: Identifying the performance driver allows you to avoid over-provisioning and reduce expenses by right-sizing servers.

Improve performance: Tuning the database for MySQL query performance optimization results in valuable performance improvements and enhanced functionality.

Improved data retrieval: The optimized MySQL database enables faster data retrieval, reducing latency and improving the overall user experience.

Reduced task load: A properly tuned database reduces the load of unnecessary tasks, optimizing system resources and improving efficiency.

Optimized data storage: Information gained from performance tuning can help determine whether and to what extent moving data storage or adding server capacity will improve performance.

Increased scalability: Performance tuning enables better scalability, allowing the database to handle increasing data loads without compromising performance.

Increased cost-effectiveness: Improved database performance and optimized resource utilization lead to a higher return on investment (ROI) by maximizing system efficiency and reducing operational costs.

Tips to effectively optimize MySQL server performance

Optimizing MySQL performance is critical to ensure that the database operates efficiently and effectively, which impacts business operations.

This section covers some MySQL performance tuning techniques that you can apply to improve the speed and efficiency of MySQL queries, reduce the risk of database failures, and optimize database performance.

Indexing strategies to optimize MySQL performance

Selecting a PHP script for your learning management solution will involve some evaluation, as there are many options and factors to consider. Here are some evaluation criteria to think about when you are selecting the best PHP LMS scripts for your context:


Fuente: devart

Avoiding the use of functions in predicates

A database does not use an index if it has any predefined function in the column.

For example:


Because of the UPPER() function, this database does not use the COL1 index. If there is no way to bypass that function in SQL, you must create a new index based on the function or generate custom columns in the database to improve performance.

Avoid using a wildcard (%) at the beginning of a predicate.

A database does not use an index if it has any predefined function in the column.

For example:


In most cases, this use of wildcards leads to significant performance limitations.

Avoid Unnecessary Columns in Select Clause

Instead of using ‘SELECT *’, always specify columns in the SELECT clause to improve MySQL performance. Because unnecessary columns cause additional load on the database, slowing down its performance as well as the whole systematic process.

Use Inner Join instead of Outer Join


Fuente: devart

Use the outer join only when necessary. Its unnecessary use not only limits database performance, but also limits MySQL query optimization options, resulting in slower execution of SQL statements.

Use DISTINCT and UNION only if necessary.

Using UNION and DISTINCT operators without any important purpose causes unwanted sorting and slows down SQL execution. Instead of UNION, using UNION ALL brings more efficiency to the process and improves MySQL performance more accurately.

Where to use "ORDER BY"

The ORDER BY keyword sorts the result set into predefined statement columns. Although the statement is an advantage for database administrators to get the sorted data, it also affects the performance of SQL execution a little bit. Because the query first needs to sort the data to produce the final result, causing a somewhat complex operation in SQL execution.

Optimization of MySQL subqueries

The most important advice I can give you about subqueries is that you should prefer a join whenever possible, at least in current versions of MySQL.

Subqueries are the subject of intense work by the optimizer team, and upcoming versions of MySQL may have more subquery optimizations.

Check which of the optimizations will end up in the released code and how much difference they will make. My point here is that “prefer a join” is not future-proof advice. The server is getting smarter, and the cases where you have to tell it how to do something rather than what results to return are becoming fewer and fewer.

Optimize your queries

Queues can affect your database performance from the core and could enter your application databases without your knowledge. For example, if you set a state for a particular item so that a “relevant process” can access it, you inadvertently create a queue. What you do is that you accumulate extra load time to access the resource for no good reason.

Queues cause problems for two main reasons. They serialize your workload, preventing the completion of tasks in parallel, and often result in a table containing work in process and historical data of jobs already completed. This adds latency to the application and makes MySQL performance tuning difficult.

Security measures to maintain optimal MySQL performance

A critical aspect of maintaining optimal MySQL performance is implementing strong security measures.

As the amount of data that organizations need to store and manage continues to grow, ensuring optimal MySQL database performance becomes increasingly important.

To ensure optimal MySQL performance, it is essential to implement security measures such as;

Protection against unauthorized access

Implementing MySQL security measures is crucial to protect against unauthorized access, which can lead to data breaches and loss, and also affect database performance and availability. Breaches can result in significant financial losses and reputational damage to companies.

To prevent unauthorized access, strong passwords and multi-factor authentication are essential. Weak passwords make it easy for hackers to gain access, while multi-factor authentication adds an additional layer of security, even if a password is compromised. Role-based access controls can also limit access to specific parts of the database, reducing the risk of unauthorized access to critical data.

Prevent SQL injection attacks

SQL injection attacks are common cyber-attacks in which malicious SQL statements are injected into MySQL queries to gain unauthorized access. These attacks can cause MySQL database performance problems, crashes or even complete failures.

It is crucial to sanitize user input and use prepared statements to prevent SQL injection attacks. Sanitizing user input involves validating and filtering the input to ensure that it meets the expected criteria, such as data type or format. Prepared statements are precompiled SQL statements that separate user input from SQL code, thus preventing SQL injection attacks.

Ensure data integrity

Data integrity is critical to maintaining optimal MySQL performance. Data loss or corruption can severely impact MySQL database performance, resulting in data inconsistency or loss of critical business information. Therefore, it is essential to implement security measures that ensure data integrity, such as backups and disaster recovery plans.

Regular backups can help ensure that critical data is not lost during a security breach or other disaster. Backups can be stored offsite or in the cloud to prevent data loss due to physical disasters such as fire, flood or theft. Disaster recovery plans can also help quickly restore databases in the event of a security breach, minimizing downtime and preventing data loss.

Compliance requirements

Many industries have data security and privacy requirements, such as the Payment Card Industry Data Security Standard (PCI DSS) and the General Data Protection Regulation (GDPR).

Failure to comply with these requirements can result in significant financial penalties and damage a company’s reputation. Implementing robust security measures can ensure compliance with these regulations and reduce the risk of non-compliance.

Server and hardware configuration in MySQL performance tuning

You need four fundamental resources to run the database. CPU, disk, memory and network. If any one of these is not functioning properly, it ultimately affects the database server and results in poor performance.

To understand the fundamental resources properly, you need to focus on two areas in particular, namely choosing the right hardware and troubleshooting problems with it.

CPU: The CPU executes queries and processes data in the database. To ensure optimal MySQL performance, it is important to choose a CPU with a high clock speed and multiple cores.

RAM: MySQL databases rely heavily on RAM to cache data and perform in-memory operations. To improve MySQL performance, it is important to ensure that the server has enough RAM to accommodate the database size and workload.

Storage: The type of storage used for the MySQL database can also significantly affect performance. Solid state drives (SSD) are generally faster than traditional hard disk drives (HDD) and can improve MySQL database performance.

Network: The speed and reliability of the network connection between the MySQL server and the clients can also affect performance.

Server configuration: Finally, server configuration can also significantly affect MySQL performance. Configuring MySQL to use appropriate buffer sizes, thread pools and other settings can improve performance and reduce the need for disk access.

Whether it is PHP benchmarking or problem solving, always check the performance of all critical resources. Qualitatively validate that they are performing according to the improvement needs in the standards. Performing this audit on a regular basis will quickly resolve any major issues that arise.

Pagination queries

Applications with pagination can overload the server, as they often group and sort data in ways that do not use indexes and use LIMIT and offset, which generates and discards rows, causing unnecessary work for the server.

Optimizations can be made in the user interface by showing a link to the next page instead of showing the exact number of pages in the results and links to individual pages. Irrelevant pages can also be prevented from being accessed.

On the query side, instead of using LIMIT with scrolling, it may be more effective to select an additional row and designate it as the starting point for the next result set. For example, if the user has viewed rows 101 to 120, the query for rows greater than or equal to 121 with a limit of 21 can be used to display the next page.

MySQL performance tuning: MySQL Query Caching

Another important aspect of performance measurement is content caching. MySQL provides database query caching, which caches the text of the SELECT statement and the retrieved result.

Therefore, every time you do a database replication, call the MySQL query cache, it will respond and display the result from the cache, and no call will be parsed repeatedly. In this way, you can maximize the MySQL cache optimization process.

To configure the MySQL query cache, you need to add some settings to MySQL. First, you should check whether the query cache is available or not with the following command:

					    mysql> SHOW VARIABLES LIKE 'have_query_cache';

This will show the result, YES. This means that the MySQL cache is working fine.

    | Variable_name    | Value |
    | have_query_cache | YES   |

Now, you can configure the MySQL query cache size and type. Remember, the default minimum size is 40KB. The maximum size can be 32MB. You can configure the MySQL query_cache_size using the following command:

					    mysql> SET GLOBAL query_cache_size = 40000;

The type of query cache can determine the behavior of all connections. You can also disable the query cache for queries such as:

					    mysql> SET SESSION query_cache_type = OFF;

You can also set values such as 0, 1 and 2 to configure the connection status.

Using Memcached for MySQL Caching

Memcached is a popular open source caching system that can be used to cache query results or other data in memory.

queries or other data in memory. MySQL can be configured to use Memcached as a plugin, allowing data to be cached and retrieved quickly.

Memcached stores the (v) values with the (k) key, and retrieves the (v) values with the (k) key without even parsing the database queries and stays away from all this hassle.

To read more about Memcached, you can read the guide on how to configure Memcache in PHP.

Application-level caching

Application-level caching refers to the caching of data at the application layer, typically in memory, to avoid the need to frequently access that data from a database. In a database context, this technique can be used to cache frequently accessed data or calculation results to improve the performance of an application interacting with the database.

Application-level caching can be especially useful for applications that frequently retrieve the same data or perform complex calculations on data that changes only occasionally. This occurs when an application needs to retrieve data from a database. First, you can check to see if the data is already cached.

Content distribution network

CDNs are commonly used to cache static assets, such as images, videos and JavaScript files, to improve the speed and performance of websites and applications. When a user requests content from a website or application, the CDN server closest to the user serves the content.

By caching content in a CDN, database load can be reduced, resulting in faster response times and increased scalability.

For example, a website that displays product images can store those images in a CDN, which will cache the images and serve them quickly to users, reducing database load and improving website performance.


We have shared exclusive best practices and tips for improving MySQL database performance, making it a comprehensive guide for backend developers looking to address poor database performance.

By implementing these tips, you can optimize your database performance, reduce query times and improve the overall user experience. Whether your goal is to improve performance or scalability, these tips are useful for anyone looking to optimize their MySQL database.

If you want to add your thoughts on the topic or want to ask some questions about it, feel free to post your comments in the comments section.

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