MySQL: performance optimization when using JSON functions in large datasets with GROUP BY
I'm stuck on something that should probably be simple... I'm stuck on something that should probably be simple. I'm experiencing important performance optimization when I try to run a query that uses JSON functions on a large dataset in MySQL 8.0. The query aggregates data using `GROUP BY` and also involves a JSON column to manipulate and extract values. The dataset contains over 500,000 rows, and the query takes several minutes to execute. Here’s a simplified version of my query: ```sql SELECT user_id, JSON_UNQUOTE(JSON_EXTRACT(data, '$.status')) AS status, COUNT(*) AS total FROM user_data GROUP BY user_id, status; ``` I've already created an index on `user_id` and am using the `EXPLAIN` statement to analyze the query. The output indicates that MySQL is performing a full table scan, which I suspect is the reason for the slow performance. I’ve tried to optimize the JSON extraction by using `JSON_UNQUOTE` directly in the group by clause, but it hasn't improved the execution time. Additionally, I’m aware that using JSON functions can lead to inefficiencies, especially with large datasets. I’ve considered restructuring the database to store relevant fields in separate columns instead of a JSON column, but that would require important changes to the application logic. Is there a way to optimize this query without changing the database structure? Are there best practices for using JSON functions in MySQL that I might be missing? Any advice or profiling techniques that could help identify the bottlenecks would be greatly appreciated! Any ideas what could be causing this? My development environment is Windows. Has anyone else encountered this? I'd be grateful for any help.