[
https://issues.apache.org/jira/browse/SPARK-59643?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
ASF GitHub Bot updated SPARK-59643:
-----------------------------------
Labels: pull-request-available (was: )
> Tighten CheckOverflow nullability to match MakeDecimal
> ------------------------------------------------------
>
> Key: SPARK-59643
> URL: https://issues.apache.org/jira/browse/SPARK-59643
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 4.1.0
> Environment: h2. Summary
> {{CheckOverflow}} declares {{override def nullable: Boolean = true}}
> unconditionally. Its sibling {{MakeDecimal}} (immediately above it in the
> same file, {{decimalExpressions.scala}}) already declares the accurate form
> {{override def nullable: Boolean = child.nullable || nullOnOverflow}} and
> guards its generated {{isNull}} assignment accordingly. {{CheckOverflow}} was
> simply never updated to match, so it over-declares nullability.
> h2. Why it matters
> {{CheckOverflow}} rounds a decimal to a target precision/scale; on overflow
> it returns {{null}} when {{nullOnOverflow}} is true and *throws* when it is
> false (ANSI). So the result is {{null}} only when the input is {{null}}, or
> when {{nullOnOverflow}} is true and an overflow occurs -- i.e.
> {{child.nullable || nullOnOverflow}}. Declaring it unconditionally nullable
> is inaccurate: under ANSI ({{nullOnOverflow = false}}), a decimal expression
> wrapped in {{CheckOverflow}} over non-nullable inputs is reported as nullable
> when it can never actually be null.
> h2. Changes
> In {{sql/catalyst/.../expressions/decimalExpressions.scala}}, aligning
> {{CheckOverflow}} with {{MakeDecimal}}
> Reporter: David Mollitor
> Priority: Trivial
> Labels: pull-request-available
>
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
