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https://issues.apache.org/jira/browse/FLINK-20670?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Shuo Cheng updated FLINK-20670:
-------------------------------
Description:
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.
was:
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.
> 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
> Fix For: 1.13.0
>
>
> 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.
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