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https://issues.apache.org/jira/browse/HIVE-16407?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Naveen Gangam resolved HIVE-16407.
----------------------------------
Resolution: Fixed
This is not reproducible on {{master}} because it uses CBO. Rule-based
optimizer is not invoked.
This testcase performs very poorly in Hive 1.1. Since then HIVE-11141,
HIVE-11671 and HIVE-11842 has been committed that seem to improve performance
and provide stability. WIthout these fixes, the query compilation would not
complete for over 90+ minus that lead to HS2 restart (query backlog pileup).
With these fixes, the query takes about 4 minutes to compile with 2800
{{%like%}} conditions.
Closing this as a fix is no longer required.
> Compilation of a query with lots of "OR" conditions (like 2200) that check
> for "like" condition take a lot of time.
> -------------------------------------------------------------------------------------------------------------------
>
> Key: HIVE-16407
> URL: https://issues.apache.org/jira/browse/HIVE-16407
> Project: Hive
> Issue Type: Improvement
> Components: HiveServer2
> Reporter: Sudarshan
> Assignee: Naveen Gangam
> Attachments: issue_reproduce.sql
>
>
> Following is the table structure.
> ----
> create table test_hello (
> a string);
> ----
> A query that involves lots of "OR" conditions can in a "where" clause, can
> take a really long time to compile. It doesn't finishes compilation in even
> 30 to 40 minutes.
> ++++
> select * from test_hello
> where
> (
> a like '%1%' or
> <Repeat above line 2000 times>
> a like '%1%'
> )
> +++++
> (Attaching the entire script to the Jira)
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