Data engineering·Time and correctness in streams
every event lands in exactly one five-minute bucket and the buckets sit end to end with no gaps.
Tumbling window
Also calledfixed window, hopping window with no overlap
Fixed-length, non-overlapping windows: each record belongs to exactly one. It is the shape almost every reporting requirement actually wants — hourly totals, daily counts — because each result is independent and sums cleanly. Its edges are arbitrary, which is the only real complaint against it: a burst straddling 14:59 and 15:01 shows as two unremarkable windows rather than one spike.