ASF GitHub Bot logged work on HIVE-23768:

                Author: ASF GitHub Bot
            Created on: 02/Jul/20 17:07
            Start Date: 02/Jul/20 17:07
    Worklog Time Spent: 10m 
      Work Description: jcamachor merged pull request #1186:
URL: https://github.com/apache/hive/pull/1186


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Issue Time Tracking

            Worklog Id:     (was: 454089)
    Remaining Estimate: 0h
            Time Spent: 10m

> Metastore's update service wrongly strips partition column stats from the 
> cache
> -------------------------------------------------------------------------------
>                 Key: HIVE-23768
>                 URL: https://issues.apache.org/jira/browse/HIVE-23768
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Stamatis Zampetakis
>            Assignee: Stamatis Zampetakis
>            Priority: Critical
>          Time Spent: 10m
>  Remaining Estimate: 0h
> Metastore's update service wrongly strips partition column stats from the 
> cache in an attempt to update them. The issue may go unnoticed since missing 
> stats do not lead to query failures. 
> However, they can alter significantly the query plan affecting performance. 
> Moreover, they lead to flakiness since some times the stats are present and 
> sometimes are not leading to a query that has a different plan overtime. 
> Normally missing elements from the cache shouldn't be a correctness problem 
> since we can always fallback to the raw stats. Unfortunately, there are many 
> interconnections with other parts of the code (e.g., code to obtain aggregate 
> statistics) where this contract breaks.   

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