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https://issues.apache.org/jira/browse/SPARK-15616?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15610024#comment-15610024
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Franck Tago commented on SPARK-15616:
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Does spark currently support pruning statistics for hive table partitions?
The question is consider an rdd that consists of
hive table 1 --- filter -- join
/
large hive table2 -----------
where the hive table1 and hive table 2 exceed the
spark.sql.autoBroadcastJoinThreshold.
However , the filter only removes data from a single partition that is small
enough to fit spark.sql.autoBroadcastJoinThreshold.
The question is , will spark perform a broadcast join in this case ?
Using spark 2.0.0 and spark 2.0.1 my observations are that spark will not.
Any ideas?
> Metastore relation should fallback to HDFS size of partitions that are
> involved in Query if statistics are not available.
> -------------------------------------------------------------------------------------------------------------------------
>
> Key: SPARK-15616
> URL: https://issues.apache.org/jira/browse/SPARK-15616
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Reporter: Lianhui Wang
>
> Currently if some partitions of a partitioned table are used in join
> operation we rely on Metastore returned size of table to calculate if we can
> convert the operation to Broadcast join.
> if Filter can prune some partitions, Hive can prune partition before
> determining to use broadcast joins according to HDFS size of partitions that
> are involved in Query.So sparkSQL needs it that can improve join's
> performance for partitioned table.
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