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https://issues.apache.org/jira/browse/HIVE-26559?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Stamatis Zampetakis updated HIVE-26559:
---------------------------------------
Fix Version/s: (was: All Versions)
I cleared the fixVersion field since this ticket is still open. Please review
this ticket and if the fix is already committed to a specific version please
set the version accordingly and mark the ticket as RESOLVED.
According to the [JIRA
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> Skip unnecessary get all partition operations when where condition with 1=0
> in CBO.
> -----------------------------------------------------------------------------------
>
> Key: HIVE-26559
> URL: https://issues.apache.org/jira/browse/HIVE-26559
> Project: Hive
> Issue Type: Improvement
> Components: CBO
> Affects Versions: All Versions
> Reporter: shuaiqi.guo
> Assignee: shuaiqi.guo
> Priority: Major
> Attachments: HIVE-26559.patch
>
> Original Estimate: 1h
> Remaining Estimate: 1h
>
> In some cases, queries may get executed with where condition mentioning to
> "1=0" to get schema. E.g
> {noformat}
> SELECT
> *
> FROM
> table_with_millions_of_partitions
> WHERE
> 1=0
> {noformat}
> In actual production, it likes:
> {noformat}
> SELECT
> *
> FROM
> table_with_millions_of_partitions
> WHERE
> partition_col1 = value1
> and partition_col2 = value2
> and if(some conditions, true, false)
> {noformat}
>
> When the cbo optimizer optimizes the execution plan of this query, the cbo
> optimizer will get all the partitions of table_with_millions_of_partitions.
> This seems useless and causes hiveserver to fail when the number of
> partitions is very high.
>
> Use this patch to skip unnecessary get all partition operation when pruneNode
> is always false.
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