概要
Provides expert guidance on transforming slow-performing SQL queries into efficient, production-ready code while strictly maintaining semantic equivalence. This skill specializes in identifying common bottlenecks such as correlated subqueries and redundant computations, offering proven architectural patterns like Common Table Expressions (CTEs) and window functions. It emphasizes a systematic verification workflow, including database-native timing and checksum-based output comparison, to ensure that optimizations deliver measurable performance gains without altering result sets.