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Posted to dev@flink.apache.org by "Jark Wu (JIRA)" <ji...@apache.org> on 2019/04/12 15:39:00 UTC

[jira] [Created] (FLINK-12173) Optimize "SELECT DISTINCT" into Deduplicate with keep first row

Jark Wu created FLINK-12173:
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             Summary: Optimize "SELECT DISTINCT" into Deduplicate with keep first row
                 Key: FLINK-12173
                 URL: https://issues.apache.org/jira/browse/FLINK-12173
             Project: Flink
          Issue Type: New Feature
          Components: Table SQL / Planner
            Reporter: Jark Wu


The following distinct query can be optimized into deduplicate on keys "a, b, c, d" and keep the first row.

{code:sql}
SELECT DISTINCT a, b, c, d;
{code}

We can optimize this query into Deduplicate to get a better performance than GroupAggregate.



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