[supriyo-biswas]

I personally like the ER diagram viewer in DBeaver. On a project with very little documentation, it was extremely pleasing to point it to the staging database and be able to visualize the relationships between various entities.

[NewJazz]

SchemaSpy can generate static docs based on a live db, and they include pretty good ER diagrams (IMO).

They have a sample on their website (go to the relationships section):

https://schemaspy.org/samples/epivirusurf/

The convenience factor is that you don't need a continuous connection to the db to refer to the diagrams or other docs.