One of the problems with running the application code inside the database server is that you need to make application developers use the programming language(s) you prepared for them. The other is that you need to trust them to not do crash out, or do infinite loops. Good luck moving application developers from their choice into the right choice.

This is easy to fix. The SpacetimeDB folks could just add a phase to analyze the application developer’s code before running it to prove that it will definitely halt.

This is why you need to compile your code for spacetimedb to WebAssembly and it runs inside a VM. Use the language of your choice, and assume the code is only semi-trusted with the ability to have a watchdog. That part makes sense.