[jira] [Commented] (HIVE-11786) Deprecate the use of redundant column in colunm stats related tables

["Pengcheng Xiong (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-11786?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14739130#comment-14739130 ] 

Pengcheng Xiong commented on HIVE-11786:
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I totally agree that these redundant columns violate database normalization rules and cause a lot of inconvenience. I also suffered a lot before. It seems to be a big change? also cc'ing [~ashutoshc] and [~alangates] to watch if it will affect HBase based metastore? Thanks.

> Deprecate the use of redundant column in colunm stats related tables
> --------------------------------------------------------------------
>
>                 Key: HIVE-11786
>                 URL: https://issues.apache.org/jira/browse/HIVE-11786
>             Project: Hive
>          Issue Type: Bug
>          Components: Metastore
>            Reporter: Chaoyu Tang
>            Assignee: Chaoyu Tang
>
> The stats tables such as TAB_COL_STATS, PART_COL_STATS have redundant columns such as DB_NAME, TABLE_NAME, PARTITION_NAME since these tables already have foreign key like TBL_ID, or PART_ID referencing to TBLS or PARTITIONS. 
> These redundant columns violate database normalization rules and cause a lot of inconvenience (sometimes difficult) in column stats related feature implementation. For example, when renaming a table, we have to update TABLE_NAME column in these tables as well which is unnecessary.
> This JIRA is first to deprecate the use of these columns at HMS code level. A followed JIRA is to be opened to focus on DB schema change and upgrade.



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