How can the correctness and performance of a database be checked?

To verify the correctness of a database, the following are usually used:

• Data validation: checking data integrity, schema compliance, constraints (e.g., uniqueness, foreign keys).
• Query testing: executing typical queries and verifying the correctness of results.
• Unit tests and integration tests: automated tests that check database operations.

To assess database performance, the following are used:

• Query profiling (e.g., EXPLAIN in SQL) to analyze execution plans and identify bottlenecks.
• Load testing with tools (JMeter, Gatling) to measure response time and throughput.
• Resource monitoring: tracking CPU, memory, disk, and network resource usage during database operation.

An example of performance testing using EXPLAIN in SQL:

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

This shows how the database plans to execute the query and helps optimize indexes.