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Jun Zhang commented on FLINK-19896: ----------------------------------- Thanks Jark, let's see how it fits into Rank operator. > Support first-n-rows deduplication in the Deduplicate operator > -------------------------------------------------------------- > > Key: FLINK-19896 > URL: https://issues.apache.org/jira/browse/FLINK-19896 > Project: Flink > Issue Type: Improvement > Components: Table SQL / Planner, Table SQL / Runtime > Reporter: Jun Zhang > Priority: Major > > Currently Deduplicate operator only supports first-row deduplication (ordered > by proc-time). In scenario of first-n-rows deduplication, the planner has to > resort to Rank operator. However, Rank operator is less efficient than > Deduplicate due to larger state and more state access. > This issue proposes to extend DeduplicateKeepFirstRowFunction to support > first-n-rows deduplication. And the original first-row deduplication would be > a special case of first-n-rows deduplication. -- This message was sent by Atlassian Jira (v8.3.4#803005)