MySQL: index and query optimization
When to use
Use this skill for index and query optimization in MySQL. This skill specifically handles index and query optimization and nothing else in the MySQL family.
Procedure
Read EXPLAIN output, add composite/covering indexes, fix non-sargable predicates, and remove unused indexes.
Notes
This is the MySQL skill dedicated to index and query optimization. Sibling skills cover other MySQL capabilities; this one is the right choice only when the task is about index and query optimization.