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Chengxiang Li commented on HIVE-10550: -------------------------------------- New added configuration: ||name||default value|| |hive.spark.dynamic.rdd.caching|true| |hive.spark.dynamic.rdd.caching.threshold|100 * 1024 * 1024L(100M)| > Dynamic RDD caching optimization for HoS.[Spark Branch] > ------------------------------------------------------- > > Key: HIVE-10550 > URL: https://issues.apache.org/jira/browse/HIVE-10550 > Project: Hive > Issue Type: Sub-task > Components: Spark > Reporter: Chengxiang Li > Assignee: Chengxiang Li > Attachments: HIVE-10550.1.patch > > > A Hive query may try to scan the same table multi times, like self-join, > self-union, or even share the same subquery, [TPC-DS > Q39|https://github.com/hortonworks/hive-testbench/blob/hive14/sample-queries-tpcds/query39.sql] > is an example. As you may know that, Spark support cache RDD data, which > mean Spark would put the calculated RDD data in memory and get the data from > memory directly for next time, this avoid the calculation cost of this > RDD(and all the cost of its dependencies) at the cost of more memory usage. > Through analyze the query context, we should be able to understand which part > of query could be shared, so that we can reuse the cached RDD in the > generated Spark job. -- This message was sent by Atlassian JIRA (v6.3.4#6332)