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Posted to issues@kylin.apache.org by "Feng Zhu (Jira)" <ji...@apache.org> on 2021/01/27 11:06:00 UTC
[jira] [Updated] (KYLIN-4888) Performance optimization of union
query with spark engine
[ https://issues.apache.org/jira/browse/KYLIN-4888?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Feng Zhu updated KYLIN-4888:
----------------------------
Description:
when using union query with spark engine, UnionPlan transforms OLAPUnionRel to spark
DataFrame, when OLAPUnionRel.all = false, distinct transformation of spark will be used, but
it's used in a loop which traversing the DataFrame collection so that there are so many stages in spark dag. Actuall, distinct transformation should be used only once at last.
was:
when using union query with spark engine, UnionPlan transforms OLAPUnionRel to spark
DataFrame, when OLAPUnionRel.all = false, distinct transformation of spark will be used, but
but it used in a loop which traversing DataFrame collection so that there are so many stages in spark dag. Actuall, distinct transformation should be used only once at last.
> Performance optimization of union query with spark engine
> ----------------------------------------------------------
>
> Key: KYLIN-4888
> URL: https://issues.apache.org/jira/browse/KYLIN-4888
> Project: Kylin
> Issue Type: Improvement
> Components: Spark Engine
> Affects Versions: v4.0.0-alpha
> Reporter: Feng Zhu
> Priority: Major
> Fix For: v4.0.0-beta
>
>
> when using union query with spark engine, UnionPlan transforms OLAPUnionRel to spark
> DataFrame, when OLAPUnionRel.all = false, distinct transformation of spark will be used, but
> it's used in a loop which traversing the DataFrame collection so that there are so many stages in spark dag. Actuall, distinct transformation should be used only once at last.
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