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https://issues.apache.org/jira/browse/DRILL-3418?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Steven Phillips updated DRILL-3418:
-----------------------------------
Attachment: DRILL-3418_2015-06-29_17:08:52.patch
> Partition Pruning : We are over-pruning and this leads to wrong results
> -----------------------------------------------------------------------
>
> Key: DRILL-3418
> URL: https://issues.apache.org/jira/browse/DRILL-3418
> Project: Apache Drill
> Issue Type: Bug
> Components: Query Planning & Optimization
> Reporter: Aman Sinha
> Assignee: Steven Phillips
> Priority: Critical
> Fix For: 1.1.0
>
> Attachments: DRILL-3418.patch, DRILL-3418_2015-06-29_15:08:57.patch,
> DRILL-3418_2015-06-29_17:08:52.patch
>
>
> git.commit.id.abbrev=c199860
> We are over-pruning based on the below plan.
> {code}
> explain plan for select * from
> `existing_partition_pruning/lineitem_hierarchical_intstring` where (dir0=1993
> or dir1='jun') and (dir0=1991 or dir1='aug' or columns[0] > 5000);
> 00-00 Screen
> 00-01 Project(*=[$0])
> 00-02 Project(T17¦¦*=[$0])
> 00-03 SelectionVectorRemover
> 00-04 Filter(condition=[AND(OR(=($1, 1993), =($2, 'jun')),
> OR(=($1, 1991), =($2, 'aug'), >(ITEM($3, 0), 5000)))])
> 00-05 Project(T17¦¦*=[$0], dir0=[$1], dir1=[$2], columns=[$3])
> 00-06 Scan(groupscan=[ParquetGroupScan
> [entries=[ReadEntryWithPath
> [path=/drill/testdata/ctas_auto_partition/existing_partition_pruning/lineitem_hierarchical_intstring/0_0_26.parquet],
> ReadEntryWithPath
> [path=/drill/testdata/ctas_auto_partition/existing_partition_pruning/lineitem_hierarchical_intstring/0_0_7.parquet]],
>
> selectionRoot=/drill/testdata/ctas_auto_partition/existing_partition_pruning/lineitem_hierarchical_intstring,
> numFiles=2, columns=[`*`]]])
> {code}
> We have 7 year partitions and each year has 12 further month partitions.
> I executed a count(*) query based on the above filters with & without
> partitioning in place and the values were different
> Without Partitions :
> {code}
> select count(*) from tbl_nopartitions where (dir0=1993 or dir1='jun') and
> (dir0=1991 or dir1='aug' or columns[0] > 5000);
> +---------+
> | EXPR$0 |
> +---------+
> | 14515 |
> +---------+
> 1 row selected (0.903 seconds)
> {code}
> With Partitions :
> {code}
> select count(*) from
> `existing_partition_pruning/lineitem_hierarchical_intstring` where (dir0=1993
> or dir1='jun') and (dir0=1991 or dir1='aug' or columns[0] > 5000);
> +---------+
> | EXPR$0 |
> +---------+
> | 1800 |
> +---------+
> 1 row selected (0.49 seconds)
> {code}
> The data is larger than 10 MB to upload here
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