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https://issues.apache.org/jira/browse/FLINK-13433?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16893694#comment-16893694
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Jark Wu edited comment on FLINK-13433 at 7/26/19 9:55 AM:
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Hi [~jinyu.zj], I think this is a good point. We should skip to lookup if join
key fields contain any null like what we do in
{{AbstractStreamingJoinOperator.JoinConditionWithNullFilters}}. However, please
note that, currently, the lookup key is not join key, lookup key contains
constant equivalent conditions in the WHERE clause.
was (Author: jark):
Hi [~jinyu.zj], I think this is a good point. We should skip to lookup if join
key fields contain any null like what do in
{{AbstractStreamingJoinOperator.JoinConditionWithNullFilters}}. However, please
note that, currently, the lookup key is not join key, lookup key contains
constant equivalent conditions in the WHERE clause.
> Do not fetch data from LookupableTableSource if the JoinKey in left side of
> LookupJoin contains null value
> ----------------------------------------------------------------------------------------------------------
>
> Key: FLINK-13433
> URL: https://issues.apache.org/jira/browse/FLINK-13433
> Project: Flink
> Issue Type: Task
> Components: Table SQL / Planner
> Affects Versions: 1.9.0, 1.10.0
> Reporter: Jing Zhang
> Assignee: Jing Zhang
> Priority: Minor
> Fix For: 1.10.0
>
>
> For LookupJoin, if joinKey in left side of a LeftOuterJoin/InnerJoin contains
> null values, there is no need to fetch data from `LookupableTableSource`.
> However, we don't shortcut the fetch function under the case at present, the
> correctness of results depends on the `TableFunction` implementation of each
> `LookupableTableSource`.
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