High CPU usage in Postgres: how to detect it, and how to fix it

High CPU usage in PostgreSQL databases can significantly impact application performance but is often fixable through proper monitoring and troubleshooting. Tools like the `top` command and PostgreSQL's `pg_stat_statements` module help identify CPU usage issues by allowing users to track query execution times and frequency. Inefficient queries, too many active connections, and database growth are common causes of high CPU usage. Solutions include optimizing queries, adjusting connection settings, and considering horizontal scaling through distributed SQL databases like CockroachDB to handle increased demand. Regular updates of database statistics are crucial to prevent inefficient execution plans, and while short-term fixes are possible, long-term solutions often require transitioning to a distributed database architecture.