Hi Jeff,
Many thanks for your complementary. Please allow me ask further questions: for this example,
CREATE OUTPUT WINDOW AVG_TEMP
PRIMARY KEY DEDUCED
AS SELECT ...
FROM EVENTS KEEP 30 SEC
GROUP BY EVENTS.MACHINEID ;
do you mean the system will first create an unnamed window which save the query result (SELECT XXX FROM EVENTS) for 30 seconds, and then the system will create your named window based on that unnamed window , do the group by aggregation and save the group by result? if so, in principle, can I also set KEEP on the header of the CREATE WINDOW statement as well to set the retain policy for the group by result? ( so in this one statement we could have two KEEP policies, on for NAMED WINDOW and one for UNNAMED WINDOW? )