Wrong results for join post tumble grouping

[Satyam Shekhar]

Hello,

I have a table T0 with the following schema -

root
      |-- amount: BIGINT}}
      |-- timestamp: TIMESTAMP(3)

The table T0 has two rows -

amount	timestamp
0	0
1	86400000

The following query with tumble grouping returns the wrong result -

WITH CTE AS
  (SELECT SUM(amount) AS _output,
          TUMBLE_END(`timestamp`, INTERVAL '1' SECOND) AS _dim0
       FROM T0 GROUP BY TUMBLE(`timestamp`, INTERVAL '1' SECOND))
SELECT V0._output as V0_output, V1._output AS V1_output, 
       V0._dim0 as V0_time, V1._dim0 as V1_time
   FROM CTE as V0 INNER JOIN CTE V1 ON V0._dim0 = V1._dim0

 

The returned result is -

V0_output	V1_output	V0_time	V1_time
1	1	86401000	86401000

The expected result is -

V0_output	V1_output	V0_time	V1_time
0	0	1000	1000
1	1	86401000	86401000

Running subquery for `CTE` returns the correct result -

SELECT SUM(amount) AS _output,
               TUMBLE_END(`timestamp`, INTERVAL '1' SECOND) AS _dim0
    FROM T0 GROUP BY TUMBLE(`timestamp`, INTERVAL '1' SECOND)

Result (this is correct) -

_output	_dim0
0	1000
1	86401000

Also, the following query without tumble grouping returns the correct result -

WITH CTE AS
  (SELECT amount AS _output, `timestamp` AS _dim0 FROM T0)
SELECT V0._output as V0_output, V1._output AS V1_output, 
       V0._dim0 as V0_time, V1._dim0 as V1_time
   FROM CTE as V0 INNER JOIN CTE V1 ON V0._dim0 = V1._dim0

Result -

V0_output	V1_output	V0_time	V1_time
0	0	0	0
1	1	86400000	86400000

I have filed a JIRA for the issue - https://issues.apache.org/jira/browse/FLINK-19926#. Would love to get some eyes on it. 

Regards,

Satyam