The article provides a comprehensive guide on using Datadog for monitoring PostgreSQL databases, detailing the process of installing the Datadog Agent on PostgreSQL servers to visualize and optimize database performance. It explains how Datadog's integration allows for the automatic aggregation of PostgreSQL metrics through a customizable dashboard, enabling users to track key metrics such as locks, index usage, and replication delay. The text also covers setting up Datadog Database Monitoring for in-depth query-level insights, including query performance tracking and identifying bottlenecks through detailed explain plans. Additionally, the article describes how to use Datadog's Application Performance Monitoring (APM) for tracing PostgreSQL queries and services across distributed systems, offering tools for creating custom dashboards and setting alerts to monitor and improve database and application performance.