Three Ways an LLM on Your Warehouse Gets ‘Why Did Revenue Drop?’ Wrong-and How to Fix Each

Connecting a language model to your warehouse is a great and a bad diagnostic engine. Here are the three failures you’ll actually hit, each with a fix, in plain SQL. Plug an LLM into your warehouse, type “why did revenue drop 8% last week?”, and you get a confident paragraph in forty seconds. It feels like the analyst bottleneck just disappeared. Then you start checking the answers, and three problems show up-in order, each quieter than the last. None of them throws an error. Here’s each one on a real Postgres example, and what fixes it.