University doesn't generally teach DB with any real vigor. I personally do not have a CS degree but I have been in tech for a long time and I have a lot of dat

University doesn't generally teach DB with any real vigor. I personally do not have a CS degree but I have been in tech for a long time and I have a lot of data side experience. When I hire new grads they commonly lack basic common DB skills even when coming out of very high end CS programs. There are exceptions of course, but as a general rule this isn't what a CS degree gets you. I find people that come out of bootcamps (DBA and developer) know more relevant DB skills than do new grads. That said. Postgres, MySQL or any relational database is a good place to start for forum software. There are valid arguments to be made why a document db might be superior in some cases but honestly if I was writing a forum I'd probably look towards Postgres and if search was going to be key, I'd also likely have ElasticSearch as part of the solution. I would suggest whatever DB you chose don't chose DynamoDB for your first real attempt. DynamoDB gives experienced data engineers headaches. It isn't that Dynamo is bad, but there are very distinct tradeoffs you need to make and weigh to setup it up for your use cases. For the record I'd also avoid Cassandra for the same reason. Something like Postgres or MySQL is more forgiving when you are learning IMO. Other options could be MongoDB (people like to hate on it for issues long resolved), SimpleDB, AWS DocumentDB etc. Amazon's document DB is Mongo Compatible but uses their backend and is very easy to work with. Just some ideas. Also you could look at some of the open source forum software out there. Might help you get ideas.