Thanks for the pointer Jingsong, I don't see how proctime() is ambiguous though as it always refers to the current wall clock time. I think thats much better than adding a magic pseudocolumn.
Cheers Gyula On Tue, Apr 20, 2021 at 11:06 AM Jingsong Li <jingsongl...@gmail.com> wrote: > +1 for simplifying. > > We already have a thread of this topic: > > http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-Make-Temporal-Join-syntax-easier-to-use-td47296.html > FYI. > > Best, > Jingsong > > On Tue, Apr 20, 2021 at 4:55 PM Gyula Fóra <gyula.f...@gmail.com> wrote: > > > Hi All! > > > > Playing around with the SQL syntax for temporal join with latest table I > > feel there is some room for optimizing the current syntax to provide a > > better user experience. > > > > The current system for specifying the lookup side is: > > > > lookuptable FOR SYSTEM_TIME AS OF probe.proctime_column > > > > It feels a bit clumsy to have to define a proctime() column in the probe > > table as I think it brings no real syntactic value and just introduces an > > overhead. > > > > I think we should allow the following syntax instead: > > > > lookuptable FOR SYSTEM_TIME AS OF proctime() > > > > To me this means the same thing and Flink can easily map it to the same > > lookup join operator. Playing around with the planner logic, this is > > surprisingly simple to implement (basicly just a 2 line change). > > > > It would be good to hear some SQL expert opinions of any potential > downside > > to this. If this makes sense I am happy to contribute this change. > > > > Cheers, > > Gyula > > > > > -- > Best, Jingsong Lee >
