Can you tell the difference between rank, dense rank, and row number?

The three functions differ in how they handle ties. RANK() assigns the same rank to tied rows and skips subsequent ranks, creating gaps. DENSE_RANK() also assigns the same rank to ties but does not skip ranks, so the next distinct value gets the next consecutive rank. ROW_NUMBER() gives a unique sequential number to each row, ignoring any ties. Choose RANK() when you need to reflect the true order with gaps (e.g., leaderboard positions). Use DENSE_RANK() when you want a compact ranking without gaps. Use ROW_NUMBER() when you need a stable, unique identifier for each row, such as for pagination or deduplication.