+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
