PSETs are a low-stakes way to build muscle memory for these problems. Try as many attempts as you want before the deadline; your best attempt is what counts. Find a problem you got wrong? Retake it, resubmit, and you get full credit. The goal is to keep iterating until each concept clicks.

Code is how this material moves from notes to muscle memory. The colabs reinforce the lectures and the readings by letting you actually run the systems you're learning about: a real query plan, a real WAL trace, a real distributed job. That's where the intuition lives.