Which ranking functions do you use for ranking and bucketing data, and how do you decide which one to use?

I typically use the ANSI window functions ROW_NUMBER(), RANK(), DENSE_RANK(), and NTILE(). ROW_NUMBER() assigns a unique sequential number to each row, making it ideal when you need a strict top‑N list, such as the single highest‑paid employee. RANK() gives the same rank to tied values but leaves gaps, useful when you want to preserve relative ordering but still allow ties. DENSE_RANK() is similar to RANK() but without gaps, which is handy when you need contiguous ranking for reporting. NTILE(n) divides the result set into n buckets of roughly equal size, perfect for percentile calculations or bucketing customers into quartiles. I choose the function based on the business requirement: if ties matter and you need exact positions, use ROW_NUMBER(). If you want to show ties and maintain ranking gaps, use RANK(). For contiguous ranking, use DENSE_RANK(). For bucketing, use NTILE().