SQL performance refers to how efficiently a database management system executes SQL queries. Factors affecting performance include query complexity, indexing, and database design. Optimizing these elements can lead to faster data retrieval and improved overall system responsiveness. To enhance SQL performance, techniques such as indexing, query optimization, and database normalization are commonly employed. Indexes help speed up data access, while query optimization involves rewriting queries for better execution plans. Proper database design ensures that data is organized effectively, reducing the time needed for operations and improving user experience.