Jark Wu created FLINK-16528: ------------------------------- Summary: 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 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: {{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)