How did you improve the performance of database queries?

To improve database query performance, I applied the following approaches:

• Query optimization: rewriting complex queries, removing redundant JOINs and subqueries.
• Indexing: adding indexes on fields that are frequently used in filters or sorting.
• Caching: using query result caching (e.g., Redis) to reduce database load.
• Pagination and limiting results: loading only the necessary amount of data to avoid network and memory overload.
• Query profiling: analyzing execution plans with tools (e.g., EXPLAIN in SQL) to identify bottlenecks.

An example of an optimized query using an index:

CREATE INDEX idx_user_email ON users(email);

SELECT * FROM users WHERE email = 'example@example.com';

This significantly speeds up searches by the email field.