A possible m-CQ₁ could be: Notify me every minute of all video frames within the past 10 seconds that contains an aircraft of type "XYZ".

Clearly this m-CQ includes similar window operator. However, filtering here requires an additional join operator. Here the multimedia dependency plays a role. Since there is a dependency between the video data, and the aircraft type, we can simply use the derived stream, instead of the original stream, and then we can join based on the frame_number attribute to get the rest of the data. The query is illustrated in the next slide.