Hi John, Are you sure that the first rows of the first window are dropped? When a query with processing time windows is terminated, the last window is not computed. This in fact intentional and does not apply to event-time windows.
Best, Fabian 2018-09-17 17:21 GMT+02:00 John Stone <elliotst...@gmail.com>: > Hello, > > I'm checking if this is intentional or a bug in Apache Flink SQL (Flink > 1.6.0). > > I am using processing time with a RocksDB backend. I have not checked if > this issue is also occurring in the Table API. I have not checked if this > issue also exists for event time (although I suspect it does). > > Consider the following two queries: > > "SELECT foo, COUNT(bar) > FROM MyTable > WHERE faz = 'xyz' > GROUP BY HOP(myTime, INTERVAL '1' SECOND, INTERVAL '5' SECOND), foo" > > and > > "SELECT foo, COUNT(bar) > FROM MyTable > WHERE faz = 'xyz' > GROUP BY TUMBLE(myTime, INTERVAL '5' SECOND), foo" > > I have found in my testing for both of the above that events received in > the first 5 seconds are ignored. In other words, the first window interval > is effectively a black hole, and only events which are received starting > after the first 5 seconds of the stream being "up" are processed. > > Is this ignoring of events during the first interval a bug or intentional? > > Many thanks, > > John >
