Hi, I think the effect is pretty straight forward, the elements in a window are not purged if the trigger is only FIRE and not FIRE_AND_PURGE. Unfortunately, your question is a bit unclear about what exactly you mean by „new window“: a truly „new“ window or another triggering of the previous (non-purged) window? In the first case, it is a new window without the previous elements, in the second case the window reflects the old contents plus all changes since the last trigger.
For sliding windows, if I remember correctly, every slide is actually a different window and elements are just added repeatedly to all windows in which they belong. So window n+1 should not be affected by whether or not window n purges or not. Maybe Aljoscha (in CC) can confirm this for us. Best, Stefan > Am 13.11.2017 um 20:19 schrieb M Singh <mans2si...@yahoo.com>: > > Hi Flink Users > > I have a few questions about triggers: > > If a trigger returns TriggerResult.FIRE from say the onProcessingTime method > - the window computation is triggered but elements are kept in the window. > If there a second invocation of the onProcessingTime method will the elements > from the previous window (which were not purged) a part of the new window > computation along with new events added since the last FIRE event ? > > Secondly, how does the FIRE option affect the sliding window computation ? > > If there are any other insights/pitfalls while dealing with this, please let > me know. > > Thanks > > Mans > >
