Does anyone know if there's an open source version of DataDog Database Monitoring (https://docs.datadoghq.com/database_monitoring/) for Postgres? Or something similar to RDS Performance Insights?

https://github.com/cybertec-postgresql/pgwatch2 and https://github.com/OPMDG come to mind

oh perfect this is exactly what I was looking for

Doesn't seem like any of the above connect to DD itself, but stand alone tools. If you have or plan on working with DD I would strongly urge to install the DD Agent on the DB itself, or find a package that pushes out this data to promotheus or such and pull them into DD that way. Also, APM capabilities with SQL are awesome - don't give up on monitoring with DD because the integration to your other services and code is essential for understanding your flows and performance

Sorry I’m intentionally looking for non-DD stuff because I’m working in an environment where we don’t have DD