Hi, You might come up with some magical self join that could do the trick - join/window join the the aggregation result with self and then aggregate it again. I don’t know if that’s possible (probably you would need to write custom aggregate function) and would be inefficient. It will be easier to convert result of your SQL query into a DataStream and process it with a simple/custom DataStream operator.
Piotrek > On 5 Nov 2018, at 10:17, yinhua.dai <yinhua.2...@outlook.com> wrote: > > We have a requirement that always want to trigger a calculation on a timer > basis e.g. every 1 minute. > > *If there are records come in flink during the time window then calculate it > with the normal way, i.e. aggregate for each record and getResult() at end > of the time window.* > > *If there are no records come in flink during the time window, then send the > last calculated result.* > > I know that Flink will not trigger the calculation in the second case(when > no records come in the system during the time window), if there a solution > for me in Flink SQL? > > > > -- > Sent from: > http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/
