SELECT (Stream)

    • can be a field name, a constant, or their association, such as temperature, weather.humidity, 114514, 1 + 2 and .
    • some_interval represents a period of time. See Intervals.

    • window_type specifies the type of time window:

      2.               | HOPPING  some_interval some_interval
      3.               | SESSION  some_interval

    • Joining streams: