You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "ASF GitHub Bot (Jira)" <ji...@apache.org> on 2023/10/21 00:18:00 UTC
[jira] [Updated] (SPARK-43778) RewriteCorrelatedScalarSubquery should handle duplicate attributes
[ https://issues.apache.org/jira/browse/SPARK-43778?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
ASF GitHub Bot updated SPARK-43778:
-----------------------------------
Labels: pull-request-available (was: )
> RewriteCorrelatedScalarSubquery should handle duplicate attributes
> ------------------------------------------------------------------
>
> Key: SPARK-43778
> URL: https://issues.apache.org/jira/browse/SPARK-43778
> Project: Spark
> Issue Type: Bug
> Components: SQL
> Affects Versions: 3.4.0
> Reporter: Andrey Gubichev
> Priority: Major
> Labels: pull-request-available
> Fix For: 4.0.0
>
>
> This is a correctness problem caused by the fact that the decorrelation rule does not dedup join attributes properly. This leads to the join on (c1 = c1), which is simplified to True and the join becomes a cross product.
>
> Example query:
>
> {code:java}
> create view t(c1, c2) as values (0, 1), (0, 2), (1, 2)
> select c1, c2, (select count(*) cnt from t t2 where t1.c1 = t2.c1 having cnt = 0) from t t1
> -- Correct answer: [(0, 1, null), (0, 2, null), (1, 2, null)]
> +---+---+------------------+
> |c1 |c2 |scalarsubquery(c1)|
> +---+---+------------------+
> |0 |1 |null |
> |0 |1 |null |
> |0 |2 |null |
> |0 |2 |null |
> |1 |2 |null |
> |1 |2 |null |
> +---+---+------------------+ {code}
>
>
>
--
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