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https://issues.apache.org/jira/browse/IMPALA-6266?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Tim Armstrong updated IMPALA-6266:
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Priority: Major (was: Critical)
> Runtime filters should not have non-deterministic expression on consumer side
> -----------------------------------------------------------------------------
>
> Key: IMPALA-6266
> URL: https://issues.apache.org/jira/browse/IMPALA-6266
> Project: IMPALA
> Issue Type: Bug
> Components: Frontend
> Affects Versions: Impala 2.8.0, Impala 2.9.0, Impala 2.10.0, Impala 2.11.0
> Reporter: Csaba Ringhofer
> Priority: Major
> Labels: correctness, runtime-filters
>
> Random expressions on the consumer side of runtime filters are evaluated
> independently from the "final" join, which gives +1 chance for rows to be
> dropped. This means that the same query can return less or different rows if
> the runtime fiiter was used than if not.
> Example:
> {code}
> use tpch_parquet;
> set DISABLE_ROW_RUNTIME_FILTERING=0;
> select count(*) from supplier join nation on s_nationkey + cast(rand()*2 as
> int) = n_nationkey;
> result: 9722
> set DISABLE_ROW_RUNTIME_FILTERING=1;
> select count(*) from supplier join nation on s_nationkey + cast(rand()*2 as
> int) = n_nationkey;
> result: 9803
> {code}
> ( rand() is pseudo-random, so running the same query without changing to
> query option always returns the same result)
> Optimizations like runtime filters should have no effect on the results, even
> in case of non-deterministic expressions.
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