Use when a query is slow, when reading EXPLAIN output, when deciding on index hints, when tuning optimizer_switch flags, when using optimizer_trace, or when comparing MariaDB and MySQL optimizer behavior. Prevents the common mistake of trusting type=ALL queries in production, blindly applying USE IN
Use when a query is slow, when reading EXPLAIN output, when deciding on index hints, when tuning optimizer_switch flags, when using optimizer_trace, or when comparing MariaDB and MySQL optimizer behavior. Prevents the common mistake of trusting type=ALL queries in production, blindly applying USE INDEX without checking selectivity, leaving outdated statistics, or copying MySQL 8 optimizer assumpti