Be aware that fixed-size windows can overflow

Consider the following example:

stream<temperature> batchedTemperatures :=
   from t in all Temperature(sensorId="S001")
   within 60.0 every 60.0 select t;
from t in batchedTemperatures
   retain 5
   select count() as c { print c.toString(); }

During execution of the first query, suppose that more than 5 matching events are found within one minute. The query outputs all of the matching events as a single lot. A lot that contains more than 5 items overflows the retain window in the second query. All but the most recent five items are lost. Calculations operate on only the most recent 5 items.

Note that you are unlikely to need the query combination shown in the code example above.