[jira] [Commented] (SPARK-40963) containsNull in array type attributes is not updated from child output

["Bruce Robbins (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SPARK-40963?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17625955#comment-17625955 ] 

Bruce Robbins commented on SPARK-40963:
---------------------------------------

I'll take a stab at fixing this in the next few days.

> containsNull in array type attributes is not updated from child output
> ----------------------------------------------------------------------
>
>                 Key: SPARK-40963
>                 URL: https://issues.apache.org/jira/browse/SPARK-40963
>             Project: Spark
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 3.4.0
>            Reporter: Bruce Robbins
>            Priority: Major
>              Labels: correctness
>
> Example:
> {noformat}
> select c1, explode(c4) as c5 from (
>   select c1, array(c3) as c4 from (
>     select c1, explode_outer(c2) as c3
>     from values
>     (1, array(1, 2)),
>     (2, array(2, 3)),
>     (3, null)
>     as data(c1, c2)
>   )
> );
> +---+---+
> |c1 |c5 |
> +---+---+
> |1  |1  |
> |1  |2  |
> |2  |2  |
> |2  |3  |
> |3  |0  |
> +---+---+
> {noformat}
> In the last row, {{c5}} is 0, but should be {{NULL}}.
> At the time {{ResolveGenerate.makeGeneratorOutput}} is called for {{explode(c4)}}, {{c3}} has nullable set to false, so {{c4}}'s data type has {{containsNull}} also set to false. Later, {{c3}}'s nullability is updated and c4's data type reports containsNull = true, but two things go wrong:
> * The {{containsNull}} setting for {{c4}} is not propogated to parent operators (so the attribute {{c4}} in {{explode(c4)}} still has containsNull = false)
> * Even if it were propogated, {{generatorOutput}} for {{explode(c4)}} is already determined and won't be recalculated.
> Another example:
> {noformat}
> select c1, inline_outer(c4) from (
>   select c1, array(c3) as c4 from (
>     select c1, explode_outer(c2) as c3
>     from values
>     (1, array(named_struct('a', 1, 'b', 2))),
>     (2, array(named_struct('a', 3, 'b', 4), named_struct('a', 5, 'b', 6))),
>     (3, null)
>     as data(c1, c2)
>   )
> );
> 22/10/27 11:53:20 ERROR Executor: Exception in task 1.0 in stage 1.0 (TID 2)
> java.lang.NullPointerException
> 	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.generate_doConsume_1$(Unknown Source)
> 	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.generate_doConsume_0$(Unknown Source)
> 	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIteratorForCodegenStage1.processNext(Unknown Source)
> 	at org.apache.spark.sql.execution.BufferedRowIterator.hasNext(BufferedRowIterator.java:43)
> 	at org.apache.spark.sql.execution.WholeStageCodegenExec$$anon$1.hasNext(WholeStageCodegenExec.scala:760)
> 	at org.apache.spark.sql.execution.SparkPlan.$anonfun$getByteArrayRdd$1(SparkPlan.scala:364)
> 	
> -
> -
> -
> {noformat}



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org