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Jingsong Lee commented on FLINK-16528: -------------------------------------- +1, it is useful, should not be TOP N, should be pushed down. > Support Limit push down for streaming sources > --------------------------------------------- > > Key: FLINK-16528 > URL: https://issues.apache.org/jira/browse/FLINK-16528 > Project: Flink > Issue Type: New Feature > Components: Table SQL / Ecosystem, Table SQL / Planner > Reporter: Jark Wu > Priority: Major > Labels: usability > Fix For: 1.11.0 > > > Currently, a limit query {{SELECT * FROM kafka LIMIT 10}} will be translated > into TopN operator and will scan the full data in the source. However, > {{LIMIT}} is a very useful feature in SQL CLI to explore data in the source. > It doesn't make sense it never stop. > We can support such case in streaming mode (ignore the text format): > {code} > flink > SELECT * FROM kafka LIMIT 10; > kafka_key | user_name | lang | created_at > --------------------+-----------------+------+------------------------- > 494227746231685121 | burncaniff | en | 2014-07-29 14:07:31.000 > 494227746214535169 | gu8tn | ja | 2014-07-29 14:07:31.000 > 494227746219126785 | pequitamedicen | es | 2014-07-29 14:07:31.000 > 494227746201931777 | josnyS | ht | 2014-07-29 14:07:31.000 > 494227746219110401 | Cafe510 | en | 2014-07-29 14:07:31.000 > 494227746210332673 | Da_JuanAnd_Only | en | 2014-07-29 14:07:31.000 > 494227746193956865 | Smile_Kidrauhl6 | pt | 2014-07-29 14:07:31.000 > 494227750426017793 | CashforeverCD | en | 2014-07-29 14:07:32.000 > 494227750396653569 | FilmArsivimiz | tr | 2014-07-29 14:07:32.000 > 494227750388256769 | jmolas | es | 2014-07-29 14:07:32.000 > (10 rows) > {code} -- This message was sent by Atlassian Jira (v8.3.4#803005)