Percona Monitoring and Management (PMM) is a free, open-source platform for monitoring MySQL, PostgreSQL, MongoDB, and ProxySQL. The platform combines Prometheus for metrics collection, ClickHouse for query analytics storage, and Grafana for visualization. Key features include Query Analytics (QAN) for identifying slow queries, advisors providing automated recommendations, custom alerting, and security threat detection. No licensing costs—deploy on-premise or in cloud with full source access. Query Analytics captures detailed query metrics including execution time, rows examined, and lock time with drill-down to individual query patterns. The advisor system provides automated recommendations based on database configuration and performance patterns. Supports MySQL 5.5+, PostgreSQL 10+, MongoDB 4.0+, and MariaDB 10.0+. Page should cover: deployment options (Docker, Kubernetes, VM), Query Analytics setup, advisor recommendations system, Grafana dashboard customization, comparison with commercial monitoring tools, and scaling considerations for large deployments.