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https://issues.apache.org/jira/browse/HIVE-17634?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

liyunzhang_intel updated HIVE-17634:
------------------------------------
    Description:  In the statistics estimation([StatsRulesProcFactory|), we do 
not estimate the column stats once we set hive.stats.fetch.column.stats as 
false.Suggest to estimate the data size by column type when 
{{hive.stats.fetch.column.stats}} as false like HIVE-17634.1.patch does.  (was: 
in 
[RelOptHiveTable#updateColStats|https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/RelOptHiveTable.java#L309],
 we set {{fetchColStats}},{{fetchPartStats}} as true when call 
{{StatsUtils.collectStatistics}}
{code}

   if (!hiveTblMetadata.isPartitioned()) {
        // 2.1 Handle the case for unpartitioned table.
        try {
          Statistics stats = StatsUtils.collectStatistics(hiveConf, null,
              hiveTblMetadata, hiveNonPartitionCols, 
nonPartColNamesThatRqrStats,
              colStatsCached, nonPartColNamesThatRqrStats, true, true);
      ...
{code}

This will cause querying columns statistic from metastore even we set  
{{hive.stats.fetch.column.stats}} and {{hive.stats.fetch.partition.stats}} as 
false in HiveConf.  If we these two properties as false, we can not any column 
statistics from metastore.  Suggest to set the properties from HiveConf. )

> Estimate the column stats even not retrieve columns from 
> metastore(hive.stats.fetch.column.stats as false)
> ----------------------------------------------------------------------------------------------------------
>
>                 Key: HIVE-17634
>                 URL: https://issues.apache.org/jira/browse/HIVE-17634
>             Project: Hive
>          Issue Type: Bug
>            Reporter: liyunzhang_intel
>            Assignee: liyunzhang_intel
>         Attachments: HIVE-17634.1.patch, HIVE-17634.patch
>
>
>  In the statistics estimation([StatsRulesProcFactory|), we do not estimate 
> the column stats once we set hive.stats.fetch.column.stats as false.Suggest 
> to estimate the data size by column type when 
> {{hive.stats.fetch.column.stats}} as false like HIVE-17634.1.patch does.



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