Which window type is time-based, fixed size, non-overlapping, and gapless?

Which window type is time-based, fixed size, non-overlapping, and gapless?

• A. Hopping Window
• B. Sliding Window
• C. Session Window
• D. Tumbling Window

Answer: (D)

Windowing in streaming systems groups events into fixed time blocks. Tumbling windows are defined with a fixed duration and align to start times, producing consecutive blocks that do not overlap and leave no gaps between them. This makes them time-based with a fixed size, and ensures each moment in time belongs to exactly one window, giving gapless coverage. Other options behave differently: hopping windows use a window length with a stride that can create overlaps; sliding windows continuously move the window forward, causing the same events to appear in multiple windows; session windows are driven by inactivity gaps and can vary in length, so they’re not fixed-size or gapless.

Windowing in streaming systems groups events into fixed time blocks. Tumbling windows are defined with a fixed duration and align to start times, producing consecutive blocks that do not overlap and leave no gaps between them. This makes them time-based with a fixed size, and ensures each moment in time belongs to exactly one window, giving gapless coverage. Other options behave differently: hopping windows use a window length with a stride that can create overlaps; sliding windows continuously move the window forward, causing the same events to appear in multiple windows; session windows are driven by inactivity gaps and can vary in length, so they’re not fixed-size or gapless.