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https://issues.apache.org/jira/browse/HIVE-26312?focusedWorklogId=780318&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-780318
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ASF GitHub Bot logged work on HIVE-26312:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 10/Jun/22 13:34
Start Date: 10/Jun/22 13:34
Worklog Time Spent: 10m
Work Description: zabetak opened a new pull request, #3359:
URL: https://github.com/apache/hive/pull/3359
### Why are the changes needed?
See HIVE-26312
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Existing tests
Issue Time Tracking
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Worklog Id: (was: 780318)
Remaining Estimate: 0h
Time Spent: 10m
> Use default digest normalization strategy in CBO
> ------------------------------------------------
>
> Key: HIVE-26312
> URL: https://issues.apache.org/jira/browse/HIVE-26312
> Project: Hive
> Issue Type: Task
> Components: CBO
> Affects Versions: 4.0.0-alpha-1
> Reporter: Stamatis Zampetakis
> Assignee: Stamatis Zampetakis
> Priority: Major
> Time Spent: 10m
> Remaining Estimate: 0h
>
> CALCITE-2450 introduced a way to improve planning time by normalizing some
> query expressions (RexNodes). The behavior can be enabled/disabled via the
> following system property: calcite.enable.rexnode.digest.normalize
> There was an attempt to disable the normalization explicitly in HIVE-23456 to
> avoid rendering HiveFilterSortPredicates rule useless. However, the [way the
> normalization is disabled
> now|https://github.com/apache/hive/blob/f29cb2245c97102975ea0dd73783049eaa0947a0/ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java#L549],
> dependents on the way classes are loaded. If for some reason
> CalciteSystemProperty is loaded before hitting the respective line in
> Hive.java setting the property will not have any effect.
> After HIVE-26238 the behavior of the rule is not dependent in the value of
> the property so there is nothing holding us back from enabling the
> normalization.
> At the moment there is not strong reason to enable or disable the
> normalization explicitly so it is better to rely on the default value
> provided by Calcite to avoid running with different normalization strategy
> when the class loading order changes.
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