[jira] [Updated] (HIVE-7654) A method to extrapolate columnStats for partitions of a table

["pengcheng xiong (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-7654?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

pengcheng xiong updated HIVE-7654:
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    Attachment: Extrapolate the Column Status.docx

This file explains how the extrapolation works

> A method to extrapolate columnStats for partitions of a table
> -------------------------------------------------------------
>
>                 Key: HIVE-7654
>                 URL: https://issues.apache.org/jira/browse/HIVE-7654
>             Project: Hive
>          Issue Type: New Feature
>            Reporter: pengcheng xiong
>            Assignee: pengcheng xiong
>            Priority: Minor
>         Attachments: Extrapolate the Column Status.docx
>
>
> In a PARTITIONED table, there are many partitions. For example, 
> create table if not exists loc_orc (
>   state string,
>   locid int,
>   zip bigint
> ) partitioned by(year string) stored as orc;
> We assume there are 4 partitions, partition(year='2000'), partition(year='2001'), partition(year='2002') and partition(year='2003').
> We can use the following command to compute statistics for columns state,locid of partition(year='2001')
> analyze table loc_orc partition(year='2001') compute statistics for columns state,locid;
> We need to know the “aggregated” column status for the whole table loc_orc. However, we may not have the column status for some partitions, e.g., partition(year='2002') and also we may not have the column status for some columns, e.g., zip bigint for partition(year='2001')
> We propose a method to extrapolate the missing column status for the partitions.



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