At one time I had a diagram of our database schema. Every table with its columns and data types was in its own now with arrows indicating foreign key relationships. Each table was color coded and then then grouped into related areas of concern (user tables over here, retailer tables over there, etc.) We had our print shop print it out at the largest size they could (about 3x5 feet) and hung it on the wall. We referred to it all the time, but it was a pain to maintain as the schema changed and overtime it became too much of a hassle so we stopped updating it. I think the same thing would happen with a system diagram. It sounds good and is helpful, but over time it won’t be maintained and will be abandoned.
Full ERDs have always been more valuable to me in the making than in the having largely for that reason. But I've gotten a lot of mileage out of generating ephemeral slices of the foreign key graph from the "viewpoint" of a given table, as here: https://di.nmfay.com/exploring-databases-visually
Theoretically a proper tool would be able to generate this on the fly - lots of tools to do this on the database side. I’m not aware of many good tools that can do this on the application side - perhaps someone can chime in with some platform specific examples?
I think a tool that did that based on naming conventions would be pretty neat - group tables if they share a prefix “user_” for example. Seems like it would be a straightforward enough implementation in some existing tooling.
Yeah.. in a world with infinite time and no compromise, documentations + diagrams are nice. In practice, working on this means not working on something else, potentially more important. Trade-offs are hard and not fun :(
