I've been playing w/ this product self-hosted for a few weeks. It can join across multiple tables, windowing functions. I haven't tried self-joins yet, nor I have put much effort into tuning w/ Golden SQL or other documentation.

I would put this at the skill level of a junior data engineer. It's pretty impressive.

For large databases, LLMs do not perform well if you pass the entire schema (either run into context window issues or confuse the LLM with too much info). There is a schema linking step that identifies the relevant schema and only passes that. The schema linking is also done in the fine-tuning process.