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Posted to issues@spark.apache.org by "Saktheesh Balaraj (JIRA)" <ji...@apache.org> on 2017/10/03 09:53:02 UTC
[jira] [Comment Edited] (SPARK-14172) Hive table partition
predicate not passed down correctly
[ https://issues.apache.org/jira/browse/SPARK-14172?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16189481#comment-16189481 ]
Saktheesh Balaraj edited comment on SPARK-14172 at 10/3/17 9:52 AM:
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Similar problem is observed while joining 2 hive tables based on partition columns.
*Example*
Table A having 1000 partitions (date partition and hour sub-partition) and Table B having 2 partition. when joining 2 tables based on partition it's going for full table scan in table A i.e using all 1000 partitions instead of taking 2 partitions from Table A and join with Table B.
*select * from tableA a, tableB b where a.trans_date=b.trans_date and a.trans_hour=b.trans_hour;*
(Here trans_date is the partition and trans_hour is the sub-partition on both the tables)
*Workaround*
selecting 2 partitions from table B and then do lookup on Table A
step1: select trans_date and a.trans_hour from table B
step2: select * from tableA where trans_date=<substitute from step1> and a.trans_hour =<substitute from step1>
was (Author: saktheesh):
Similar problem is observed while joining 2 hive tables based on partition columns.
*Example*
Table A having 1000 partitions (date partition and hour sub-partition) and Table B having 2 partition. when joining 2 tables based on partition it's going for full table scan in table A i.e using all 1000 partitions instead of taking 2 partitions from Table A and join with Table B.
*select * from tableA a, tableB b where a.trans_date=b.trans_date and a.trans_hour=b.trans_hour;*
(Here trans_date is the partition and trans_hour is the sub-partition on both the tables)
*Workaround: *
selecting 2 partitions from table B and then do lookup on Table A
step1: select trans_date and a.trans_hour from table B
step2: select * from tableA where trans_date=<substitute from step1> and a.trans_hour =<substitute from step1>
> Hive table partition predicate not passed down correctly
> --------------------------------------------------------
>
> Key: SPARK-14172
> URL: https://issues.apache.org/jira/browse/SPARK-14172
> Project: Spark
> Issue Type: Bug
> Components: SQL
> Affects Versions: 1.6.1
> Reporter: Yingji Zhang
> Priority: Critical
>
> When the hive sql contains nondeterministic fields, spark plan will not push down the partition predicate to the HiveTableScan. For example:
> {code}
> -- consider following query which uses a random function to sample rows
> SELECT *
> FROM table_a
> WHERE partition_col = 'some_value'
> AND rand() < 0.01;
> {code}
> The spark plan will not push down the partition predicate to HiveTableScan which ends up scanning all partitions data from the table.
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