Wanderloop

One of the visions of joblib is to avoid computing the same thing twice. Joblib proved pretty useful to me while doing ML @Wanderloop. Joblib saves your entire sklearn pipeline in .joblib file format that can be reused by uploading the file to the session and obviously a one-line code snippet. It comes in handy when different models produce desired results with the same hyperparameters.

MySQL 8.0 is significantly better than MySQL 5.7. For all InnoDB row operations, you'll see a great performance improvement. Also, the time taken to process transactions is lower in MySQL 8.0. Moreover, there has been an improvement in managing read and read/write workloads.

Since you are trying to make a Roblox game, you have no other option than to use Lua, since Roblox only allows coding in Lua. Yes, you've heard right, Python is identical and as easy as Lua, although Lua is easier than Python. Beginning from Lua and then escalating to Python is recommended. Java is only helpful when you are creating a heavy, big-budget, enterprise-level product, otherwise, Python would suffice.

I would recommend a mixture of MySQL and MongoDB. Using MongoDB for the Content Distribution Network (CDN) will make it easy to store high volume incoming data. MySQL is recommended to be used for business logic. PostgreSQL is not recommended since you will be faced with inefficient database replication features and constant migration from one PostgreSQL version to another.