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https://issues.apache.org/jira/browse/SPARK-60028?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Yang Jie updated SPARK-60028:
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Affects Version/s: 4.1.3
4.0.3
4.2.0
3.5.8
> LikeSimplification duplicates a nondeterministic input of a single-pattern
> LIKE
> -------------------------------------------------------------------------------
>
> Key: SPARK-60028
> URL: https://issues.apache.org/jira/browse/SPARK-60028
> Project: Spark
> Issue Type: Bug
> Components: SQL
> Affects Versions: 3.5.8, 4.2.0, 4.0.3, 5.0.0, 4.1.3
> Reporter: Yang Jie
> Priority: Major
> Labels: pull-request-available
>
> For a LIKE with a single pattern of the form 'prefix%suffix',
> LikeSimplification rewrites `input LIKE pattern` into `OctetLength(input) >=
> n AND StartsWith(input, prefix) AND EndsWith(input, suffix)`, copying `input`
> three times without checking that it is deterministic. A nondeterministic
> input is then evaluated once per copy, so the predicate can be true for a row
> where no single value matches. The LikeAll/LikeAny cases already guard with
> CollapseProject.isCheap.
> Example: with a nondeterministic UDF `pick()` that returns 'ay' or 'bz' at
> random, `SELECT pick() LIKE 'a%z' AS r FROM range(0, 1000, 1, 1)` returned
> 256 true rows in one run, where the correct count is 0.
> Raised in https://github.com/apache/spark/pull/59209#discussion_r4199845624
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