MySQL 8.0 - Strange Behavior with JSON Data Type and Indexing in Queries
I'm relatively new to this, so bear with me. I keep running into I'm following best practices but I'm building a feature where I'm working on a project and hit a roadblock. I'm working on a project and hit a roadblock. I'm relatively new to this, so bear with me. I'm experiencing an odd issue while querying a table that contains a JSON column in MySQL 8.0. I have a table called `products` with a JSON column named `attributes`, where I store additional product details. The structure looks something like this: ```sql CREATE TABLE products ( id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255), attributes JSON ); ``` I indexed the JSON column using a generated column to improve query performance: ```sql ALTER TABLE products ADD COLUMN attr_color VARCHAR(50) AS (attributes->>'$.color') STORED; CREATE INDEX idx_color ON products(attr_color); ``` However, when I run the following query to filter products by color: ```sql SELECT * FROM products WHERE attr_color = 'red'; ``` I get unexpectedly slow performance, and the query seems to ignore the index. When I check the execution plan using `EXPLAIN`, it shows that a full table scan is being performed instead of using the index. Here’s the output: ``` +----+-------------+----------+------------+------+---------------+---------+---------+------+----------+-------------+ | id | select_type | table | type | key | key_len | ref | rows | Extra| +----+-------------+----------+------------+------+---------------+---------+---------+------+----------+-------------+ | 1 | SIMPLE | products | ALL | NULL | NULL | NULL | 1000 | | Using where| +----+-------------+----------+------------+------+---------------+---------+---------+------+----------+-------------+ ``` I have verified that the JSON data actually contains the color property and is formatted correctly. Additionally, I tried running the query without the index and didn’t notice a significant difference in execution time. I've also checked for MySQL variables that might affect indexing behavior, but nothing stands out. Anyone else faced something similar or have suggestions on how to optimize queries involving JSON data types? Could it be related to how MySQL handles the JSON indexing? My development environment is Ubuntu. What's the best practice here? This is part of a larger CLI tool I'm building. My development environment is macOS. Any examples would be super helpful. The stack includes Sql and several other technologies. How would you solve this?