Handling Ties in Window Functions

It's **Day 73**, and we're talking about **Determinism**.

The Mystery of the Changing Rank

Have you ever run a query twice and seen the ranks change?

This happens because your `ORDER BY` is not unique. If numbers are tied, the database chooses an order randomly based on which row it found first on the physical disk.

The Professional Solution: The Tie-Breaker

Always include a unique column (like ID) as your second sort condition.

-- Dangerous (Inconsistent)

RANK() OVER(ORDER BY score DESC)

-- Professional (Consistent)

RANK() OVER(ORDER BY score DESC, user_id ASC)

Why this matters for APIs

If your mobile app shows a leaderboard, users will be very upset if their position jumps around every time they refresh the screen!

Your Task for Today

Add a secondary `ORDER BY` column to one of your window functions to ensure the results are 100% consistent every time.

*Day 74: Window Functions vs Subqueries—A Face Off.*