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https://issues.apache.org/jira/browse/SPARK-54335?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated SPARK-54335:
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Labels: pull-request-available (was: )
> Reducing skew in the number of file splits per partition
> --------------------------------------------------------
>
> Key: SPARK-54335
> URL: https://issues.apache.org/jira/browse/SPARK-54335
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 4.1.0
> Reporter: Rong Ma
> Priority: Major
> Labels: pull-request-available
>
> Currently, when Spark partitions the input files in a table scan, it first
> sorts the input splits, then adjacent splits are coalesced into a single
> partition. If the input split size distribution is uneven, some partitions
> will have only a few splits while others will have many.
> We observed that this file partitioning strategy can slow down the reading
> process if some tasks are reading more files than others, especially in
> Gluten’s native Parquet reader. To address this performance issue, we are
> proposing a new partitioning strategy that takes both partition size and file
> count into account and distributes the small files across different
> partitions to avoid skew.
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