[ 
https://issues.apache.org/jira/browse/SPARK-49408?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Frank Wong updated SPARK-49408:
-------------------------------
    Description: 
In {*}ProjectingInternalRow{*}, the *colOrdinals* is passed as a {_}List{_}. 
According to the Scala documentation, the _{{apply}}_ method for _{{List}}_ has 
a linear time complexity, and it is used in all methods of 
ProjectingInternalRow for every row. This can have a significant impact on 
performance.

The following flame graph was captured in a {*}merge into sql{*}. A 
considerable amount of time was spent on {{{}List.apply{}}}. Changing this to 
_{{IndexedSeq}}_ would improve the performance.

 

 

[https://docs.scala-lang.org/overviews/collections-2.13/performance-characteristics.html]

  was:
In {*}ProjectingInternalRow{*}, the *colOrdinals* is passed as a {_}List{_}. 
According to the Scala documentation, the _{{apply}}_ method for _{{List}}_ has 
a linear time complexity, and it is used in all methods of 
ProjectingInternalRow for every row. This can have a significant impact on 
performance.

The following flame graph was captured in a {*}merge into sql{*}. A 
considerable amount of time was spent on {{{}List.apply{}}}. Changing this to 
_{{IndexedSeq}}_ would improve the performance.

!image-2024-08-27-19-25-50-462.png|width=549,height=86!

 

https://docs.scala-lang.org/overviews/collections-2.13/performance-characteristics.html


> Low performance in ProjectingInternalRow
> ----------------------------------------
>
>                 Key: SPARK-49408
>                 URL: https://issues.apache.org/jira/browse/SPARK-49408
>             Project: Spark
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 3.5.2
>            Reporter: Frank Wong
>            Priority: Major
>
> In {*}ProjectingInternalRow{*}, the *colOrdinals* is passed as a {_}List{_}. 
> According to the Scala documentation, the _{{apply}}_ method for _{{List}}_ 
> has a linear time complexity, and it is used in all methods of 
> ProjectingInternalRow for every row. This can have a significant impact on 
> performance.
> The following flame graph was captured in a {*}merge into sql{*}. A 
> considerable amount of time was spent on {{{}List.apply{}}}. Changing this to 
> _{{IndexedSeq}}_ would improve the performance.
>  
>  
> [https://docs.scala-lang.org/overviews/collections-2.13/performance-characteristics.html]



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

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to