Indexes are crucial for optimizing query execution times in databases, but having an excessive number of indexes, or redundant ones, can negatively impact performance. While pt-duplicate-key-checker is the go-to tool for identifying duplicate or redundant indexes in MySQL, it may not catch all duplicates.
In this blog post, we’ll put ourselves to the test and see if we can identify duplicate and redundant indexes in MySQL. Toward the end, we will identify what the pt-duplicate-key-checker doesn’t.
The unique quiz
Consider the following MySQL table definition. Let’s put our brains to work and note any of the duplicate or redundant indexes (play fair, don’t cheat):
CREATE TABLE `table_with_lot_of_trouble` ( `id` int NOT NULL, `col1` varchar(1) DEFAULT NULL, `col2` varchar(2) DEFAULT NULL, `col3` varchar(3) …[Read more]