hive-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Pengcheng Xiong (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HIVE-16274) Support tuning of NDV of columns using lower/upper bounds
Date Sun, 26 Mar 2017 00:31:41 GMT

     [ https://issues.apache.org/jira/browse/HIVE-16274?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Pengcheng Xiong updated HIVE-16274:
-----------------------------------
    Fix Version/s:     (was: 3.0.0)
                   2.3.0

> Support tuning of NDV of columns using lower/upper bounds
> ---------------------------------------------------------
>
>                 Key: HIVE-16274
>                 URL: https://issues.apache.org/jira/browse/HIVE-16274
>             Project: Hive
>          Issue Type: Bug
>    Affects Versions: 2.1.0
>            Reporter: Pengcheng Xiong
>            Assignee: Pengcheng Xiong
>             Fix For: 2.3.0
>
>         Attachments: HIVE-16274.01.patch, HIVE-16274.02.patch
>
>
> For partitioned tables, the distinct value (nDV) estimate for a column is by default
set to the largest nDV value in any of the partitions being considered, which is a lower bound
on the nDV estimate.
> This provides a config setting to allow the estimate to a specified fraction (0.0 - 1.0)
of the higher bound on the nDV estimate (the sum of all the nDVs in all partitions).



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Mime
View raw message