How can bottlenecks causing delays in SQL query execution be identified?

Several approaches are used to identify bottlenecks in SQL queries:

• EXPLAIN / EXPLAIN ANALYZE — allows obtaining the execution plan of a query, seeing which indexes are used, and which operations take the most time.
• Query profiling — using built-in DBMS tools (e.g., SQL Server Profiler, MySQL Slow Query Log) to track slow queries.
• Resource monitoring — checking CPU, disk, and network load during query execution to understand where delays occur.
• Logging and tracing — analyzing application and database logs to identify problematic queries.

Example of using EXPLAIN in PostgreSQL:

EXPLAIN ANALYZE SELECT * FROM orders WHERE customer_id = 123;

This will show how long each part of the query takes and help find bottlenecks.