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https://issues.apache.org/jira/browse/HIVE-24205?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17207989#comment-17207989
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Rajesh Balamohan commented on HIVE-24205:
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Thanks [~mustafaiman]. With repeated runs (i.e without any data miss), I see
around 9-10% improvement with the PR. This is based on a small 5 node LLAP
cluster with TPCH12 (43.82 seconds vs 39.01 seconds).
Tried with "select count(*) from lineitem where l_shipmode in ('REG AIR',
'MAIL');" which showed much better improvement with and without PR (10.94
seconds vs 8.49 seconds).
> Optimise CuckooSetBytes
> -----------------------
>
> Key: HIVE-24205
> URL: https://issues.apache.org/jira/browse/HIVE-24205
> Project: Hive
> Issue Type: Improvement
> Reporter: Rajesh Balamohan
> Assignee: Mustafa Iman
> Priority: Major
> Labels: pull-request-available
> Attachments: Screenshot 2020-09-28 at 4.29.24 PM.png, bench.png,
> vectorized.patch
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> {{FilterStringColumnInList, StringColumnInList}} etc use CuckooSetBytes for
> lookup.
> !Screenshot 2020-09-28 at 4.29.24 PM.png|width=714,height=508!
> One option to optimize would be to add boundary conditions on "length" with
> the min/max length stored in the hashes (ref:
> [https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/CuckooSetBytes.java#L85])
> . This would significantly reduce the number of hash computation that needs
> to happen. E.g
> [TPCH-Q12|https://github.com/hortonworks/hive-testbench/blob/hdp3/sample-queries-tpch/tpch_query12.sql#L20]
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