What strategies can be applied to improve the efficiency of SQL query execution and reduce database response time?

To improve the efficiency of SQL queries and reduce database response time, the following strategies can be applied:

• Use indexes to speed up searches on frequently used columns.
• Optimize queries: avoid SELECT *, use only necessary fields.
• Cache query results if data does not change often.
• Use prepared statements for recurring queries.
• Break large queries into smaller ones or use pagination.
• Analyze and optimize query execution plans using EXPLAIN.
• Minimize the number of database connections and use connection pools.

Example of using an index:

CREATE INDEX idx_user_email ON users(email);

This will speed up user searches by email.