Hi, I agree it would be great to see these functions built-in, but you do not need to write a UDF for each type. You can overload a UDFs type inference and have the same capabilities as built-in functions, which means supporting generics.
https://github.com/apache/flink/blob/master/flink-examples/flink-examples-table/src/main/java/org/apache/flink/table/examples/java/functions/LastDatedValueFunction.java On Sat, Sep 18, 2021 at 7:42 AM Yuval Itzchakov <yuva...@gmail.com> wrote: > Hi Jing, > > I recall there is already an open ticket for built-in aggregate functions > > On Sat, Sep 18, 2021, 15:08 JING ZHANG <beyond1...@gmail.com> wrote: > >> Hi Yuval, >> You could open a JIRA to track this if you think some functions should be >> added as built-in functions in Flink. >> >> Best, >> JING ZHANG >> >> Yuval Itzchakov <yuva...@gmail.com> 于2021年9月18日周六 下午3:33写道： >> >>> The problem with defining a UDF is that you have to create one overload >>> per key type in the MULTISET. It would be very convenient to have functions >>> like Snowflakes ARRAY_AGG. >>> >>> On Sat, Sep 18, 2021, 05:43 JING ZHANG <beyond1...@gmail.com> wrote: >>> >>>> Hi Kai, >>>> AFAIK, there is no built-in function to extract the keys in MULTISET >>>> <https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/dev/table/types/> >>>> to >>>> be an ARRAY. Define a UTF is a good solution. >>>> >>>> Best, >>>> JING ZHANG >>>> >>>> Kai Fu <zzfu...@gmail.com> 于2021年9月18日周六 上午7:35写道： >>>> >>>>> Hi team, >>>>> >>>>> We want to know if there is any built-in function to extract the keys >>>>> in MULTISET >>>>> <https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/dev/table/types/> >>>>> to be an ARRAY. There is no such function as far as we can find, except to >>>>> define a simple wrapper UDF for that, please advise. >>>>> >>>>> -- >>>>> *Best wishes,* >>>>> *- Kai* >>>>> >>>>
