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Jark Wu updated FLINK-20670: ---------------------------- Labels: (was: stale-major) > Support query hints for Flink SQL > --------------------------------- > > Key: FLINK-20670 > URL: https://issues.apache.org/jira/browse/FLINK-20670 > Project: Flink > Issue Type: New Feature > Components: Table SQL / API > Reporter: Shuo Cheng > Priority: Major > > Now Flink has supported dynamic table options based on the Hint framework of > Calcite. Besides this, Hint syntax is also very useful for query > optimization, as there is no perfect planner, and query hints provide a > mechanism to direct the optimizer to choose an efficient query execution plan > based on the specific criteria. > Currently, almost most popular databases and big-data frameworks support > query hint, for example, Join hints in Oracle are used as following: > {code:sql} > SELECT /*+ USE_MERGE(employees departments) */ * > FROM employees, departments > WHERE employees.department_id = departments.department_id; > {code} > Flink also have several join strategy for batch job, i.e., Nested-Loop, > Sort-Merge and Hash Join, it will be convenient for users to produce an > efficient join execution plan if Flink supports Join hint. Besides Join in > batch job, it's also possible to use join hints to support partitioned > temporal table join in future. In a word, query hint, especially join hint > now, will benefit Flink users a lot. -- This message was sent by Atlassian Jira (v8.3.4#803005)