Window functions, CTEs, query plans and the schema design questions that appear in ML interviews.
8h · 7 lessons · 1 challenge
Training data comes out of a warehouse, and the query that produces it is part of the model. This module covers SQL to the level ML engineers are actually tested at — window functions and CTEs, not SELECT star — plus enough schema design to discuss a feature table without hand-waving.
Includes reading a query plan, because "why is this slow" is the follow-up question.
Ten warehouse schemas, ten training sets to extract. Correctness first, then rows scanned — the leaderboard cares about both.
Worth 400 XP.
