Time Temporal Join

[Satyam Shekhar]

Hello folks,

I am looking to enrich rows from an unbounded streaming table by joining it
with a bounded static table while preserving rowtime for the streaming
table. For example, let's consider table two tables F and D, where F is
unbounded and D is bounded. The schema for the two tables is the following -

F:
 |-- C0: BIGINT
 |-- C1: STRING
 |-- R: TIMESTAMP(3) **rowtime**
 |-- WATERMARK FOR R: TIMESTAMP(3) AS `R` - INTERVAL '0' SECONDS

D:
 |-- C0: BIGINT
 |-- C1: STRING NOT NULL

I'd like to run the following query on this schema -

select sum(F.C0), D.C1, tumble_start(F.R, interval '1' second)
    from F join D ON F.C1 = D.C1
    group by D.C1, tumble(F.R, interval '1' second)

However, I run into the following error while running the above query -

"Rowtime attributes must not be in the input rows of a regular join. As a
workaround you can cast the time attributes of input tables to TIMESTAMP
before."

My understanding reading the docs is that Time Temporal Join is meant to
solve this problem. So I model table D as the following -

D:
 |-- C0: BIGINT
 |-- C1: STRING NOT NULL
 |-- R: TIMESTAMP(3)
 |-- WATERMARK FOR R: TIMESTAMP(3) AS `R` - INTERVAL '0' SECONDS
 |-- CONSTRAINT 2da2dd2e-9937-48cb-9dec-4f6055713004 PRIMARY KEY (C1)

With column D.R always set to 0 and modify the query as follows -

select sum(F.C0), D.C1, tumble_start(F.R, interval '1' second)
    from F join D FOR SYSTEM_TIME AS OF F.R ON F.C1 = D.C1
    group by D.C1, tumble(F.R, interval '1' second)

The above query runs but does not return any result. I have the following
data in D initially -
Emit D row=+I(0,"0",1970-01-01T00:00)@time=0
Emit D row=+I(1,"1",1970-01-01T00:00)@time=0
Emit D row=+I(2,"2",1970-01-01T00:00)@time=0
Emit D watermark=0

And F streams the following rows -
Emit F row=+I(0,"0",1970-01-01T00:00)@time=0
Emit F row=+I(1,"1",1970-01-01T00:00:10)@time=1000
Emit F watermark=1000

I expect that two rows in F will join with matching rows (on C1) in D and
produce some output. But I do not see anything in the output.

So I have the following questions -

1. Is time temporal join the correct tool to solve this problem?
2. What could be the reason for not getting any output rows in the result?

Thanks,
Satyam