Write a [DIALECT] query that answers this question: [QUESTION] Schema: [SCHEMA] Return: 1. The query, formatted and commented where a clause is non-obvious 2. Every assumption you made — especially about NULLs, duplicates, time zones and what counts as "active" 3. Any place the schema is ambiguous enough that a reasonable person would write a different query, and what you would need to know to decide 4. A rough note on what will be slow at scale and which index would fix it Do not invent columns. If the question cannot be answered from this schema, say which column is missing.
Turns numbers into the one sentence a decision-maker needs, with the caveat attached.
Writes the formula and explains it in English, so you can maintain it later.
Reads a retention table the way an analyst would, including what looks like a trend and is not.