Locating Hot I/O Objects in MySQL 8


MySQL is a robust and widely used relational database management system, but performance issues can arise as with any complex software. I/O (Input/Output) operations are often a critical consideration among the many factors affecting MySQL performance. Slow I/O can lead to bottlenecks, causing queries to lag and overall database performance to suffer.

This guide focuses on troubleshooting MySQL 8 performance by identifying and addressing Hot I/O Objects. Hot I/O Objects are tables and indexes that experience a high volume of I/O activity, making them prime candidates for optimization. By pinpointing these objects and understanding why they’re hot, you can take steps to enhance your database’s efficiency.

Identifying Hot I/O Objects

MySQL 8 provides a robust toolset for performance analysis, including the Performance Schema. To locate Hot I/O Objects, we can query the Performance Schema and the SYS Schema to gather information about I/O activity on tables and indexes.

Interpreting the Results

The script generates a list of tables and indexes based on their I/O activity, including read and write counts and times. Objects with the highest combined I/O time are considered Hot I/O Objects.


Troubleshooting MySQL 8 performance is essential for maintaining the responsiveness and reliability of your database. Identifying Hot I/O Objects through the Performance Schema is a crucial step in this process. By understanding which tables and indexes are the most I/O-intensive, you can focus your optimization efforts where they matter most.

Whether it’s optimizing queries, restructuring data, or introducing caching mechanisms, addressing Hot I/O Objects can significantly enhance MySQL performance. Regular monitoring and fine-tuning will help keep your database running smoothly even as workloads evolve.

In conclusion, leveraging the Performance Schema to find Hot I/O Objects is an effective strategy for troubleshooting MySQL 8 performance and ensuring your database meets the demands of your applications.

About Shiv Iyer 443 Articles
Open Source Database Systems Engineer with a deep understanding of Optimizer Internals, Performance Engineering, Scalability and Data SRE. Shiv currently is the Founder, Investor, Board Member and CEO of multiple Database Systems Infrastructure Operations companies in the Transaction Processing Computing and ColumnStores ecosystem. He is also a frequent speaker in open source software conferences globally.