Sql Window Functions

Window functions perform calculations across a set of rows that are related to the current row — without collapsing those rows into a single result the way GROUP BY does. ## Why this appears in interviews Window functions appear in virtua

You'll learn how this concept slots into the production systems you'll be expected to design in interviews — the same pipelines used at Anthropic, OpenAI, Cohere, and Google DeepMind.

Includes a worked example with annotated code, the common mistakes interviewers probe for, and a glossary of the terms you'll need to use fluently.