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https://issues.apache.org/jira/browse/FLINK-12971?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated FLINK-12971:
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Labels: pull-request-available (was: )
> Remove the constraint that lookup join needs a primary key or index key
> -----------------------------------------------------------------------
>
> Key: FLINK-12971
> URL: https://issues.apache.org/jira/browse/FLINK-12971
> Project: Flink
> Issue Type: Improvement
> Components: Table SQL / Planner
> Reporter: Jark Wu
> Assignee: Jark Wu
> Priority: Major
> Labels: pull-request-available
>
> Currently, we add a constraint in dimension table lookup join that the lookup
> fields must be a primary key or index key. This is not a logic constraint but
> a performance constraint. Because if there are no indexes on the lookup key,
> the lookup performance will be poor.
> We will remove this constraint because not every table have a primary key or
> indexes (e.g. Hive tables). It's the user's responsibility if the lookup
> fields are not keys and get a bad performance. In this case, users should add
> indexes on these fields. In the future, we can also propagate out these
> tuning information before SQL is executed.
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