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https://issues.apache.org/jira/browse/FLINK-7403?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Hequn Cheng updated FLINK-7403:
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Description:
Currently, we expand local references before code generation. This means that
expressions that actually only need to be evaluated once, might be evaluated
multiple times. We should remove the expand step where possible.
Take the following query as an example:
{code:java}
t.select(func0('c), func0('c), func0('c))
{code}
func0('c) is called three times for every input row even func0 is
deterministic. It would be nice if we can reuse it.
was:Currently, we expand local references before code generation. This means
that expressions that actually only need to be evaluated once, might be
evaluated multiple times. We should remove the expand step where possible.
> Remove expandLocalRef() before code generation
> ----------------------------------------------
>
> Key: FLINK-7403
> URL: https://issues.apache.org/jira/browse/FLINK-7403
> Project: Flink
> Issue Type: Improvement
> Components: Table API & SQL
> Reporter: Timo Walther
> Assignee: Hequn Cheng
> Priority: Major
>
> Currently, we expand local references before code generation. This means that
> expressions that actually only need to be evaluated once, might be evaluated
> multiple times. We should remove the expand step where possible.
> Take the following query as an example:
> {code:java}
> t.select(func0('c), func0('c), func0('c))
> {code}
> func0('c) is called three times for every input row even func0 is
> deterministic. It would be nice if we can reuse it.
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