2025-09-22

Window frames that survive messy event timestamps

Leo Han · SQL · analytics

RANGE frames behave differently across engines when event streams include late-arriving rows. We teach students to pair ROWS tests with bounded RANGE windows so dashboards stay stable.

In Window Functions Orbit, teams bring their own anonymised extracts. Coaches help them rewrite nested subqueries into readable partitions without hiding assumptions in opaque macros.

The exercise closes with a documentation pass: every window spec gets a one-line rationale in the repo README so future reviewers know which business rule it encodes.