Hey all 🙂 I’m trying to query a Kafka source and emit an aggregated value every 10 seconds using SQL. I keep getting

Initial Segment may not be null

error. I’m using Flink 1.14.5. Here’s a simplified version of the query:

SELECT
  window_start, window_end,
count(`timestamp`) as `total`
from TABLE(TUMBLE(TABLE tbl, descriptor(`timestamp`), INTERVAL '5' SECOND))
group by
 window_start, window_end

The only reference I found was an open issue in the mailing list, that I’m not sure is related. Can you please help?