Supports SQL Window Table Functions

create table L(
  lts timestamp(3),
  f0 int,
  f1 bigint,
  f2 varchar(20),
  watermark for lts as lts - '10' second
) with (
  'connector' = 'my-connector'
  ...
)

create table R(
  rts timestamp(3),
  f0 int,
  f1 bigint,
  f2 varchar(20),
  watermark for rts as rts - '10' second
) with (
  'connector' = 'my-connector'
  ...
)

select * from
table(tumble(table L, descriptor(lts), INTERVAL '5' MINUTE)) ll
join
table(tumble(table R, descriptor(rts), INTERVAL '5' MINUTE)) rr
on ll.window_start = rr.window_start and ll.window_end = rr.window_end -- should this be optional ?
and ll.f0 = rr.f0