Why keep the first row still produce update/delete rows? There was a similar question before. Jark said that keep the first line should produce an append-only stream and interval join can consume from it. The link to this question is: https://lists.apache.org/thread/z5w5n7o9g87dtb7p7q7p7vrvowqhth2d
Did the latest version of Flink change deduplication?
