What other options are there to increase database speed besides indexes?

In addition to using indexes, the following approaches can be applied to increase database performance:

• Query optimization: rewrite complex queries, use more efficient JOINs, avoid SELECT *.
• Caching: store frequently requested data in memory (e.g., Redis) for quick access.
• Denormalization: in some cases, add redundant data to reduce the number of JOINs.
• Table partitioning: split large tables into parts based on keys (dates, regions) to speed up queries.
• Using materialized views: precomputed query results.
• Configuring DBMS parameters: increase buffer sizes, tune the query planner.
• Vertical and horizontal scaling: add resources to the server or distribute the load across multiple servers.

Example of query optimization:

-- Instead of
SELECT * FROM orders WHERE customer_id = 123;

-- It's better to specify only the needed fields
SELECT order_id, order_date, total_amount FROM orders WHERE customer_id = 123;