[ 
https://issues.apache.org/jira/browse/HIVE-9480?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Xiaobing Zhou updated HIVE-9480:
--------------------------------
    Description: 
Hive already supports LAST_DAY UDF, in some cases, FIRST_DAY is necessary to do 
date/timestamp related computation. This JIRA is to track such an 
implementation. Choose to impl TRUNC, a more standard way to get the first day 
of a a month, e.g., SELECT TRUNC('2009-01-12', 'MM') FROM src LIMIT 1; will 
return 2009-01-01

BTW, this TRUNC is not as feature complete as aligned with Oracle one. 'MM' is 
the only format supported, however, it's a base to add on other formats.

  was:
Hive already supports LAST_DAY UDF, in some cases, FIRST_DAY is necessary to do 
date/timestamp related computation. This JIRA is to track such an 
implementation. Choose to impl TRUNC, a more standard way to get the first day 
of a a month, e.g., SELECT TRUNC('2009-01-12', 'MM') FROM src LIMIT 1; will 
return 2009-01-01

However, this TRUNC is not as feature complete as aligned with Oracle one. 'MM' 
is the only format supported.


> Build UDF TRUNC to implement FIRST_DAY as compared with LAST_DAY
> ----------------------------------------------------------------
>
>                 Key: HIVE-9480
>                 URL: https://issues.apache.org/jira/browse/HIVE-9480
>             Project: Hive
>          Issue Type: Bug
>          Components: UDF
>    Affects Versions: 0.14.0
>            Reporter: Xiaobing Zhou
>            Assignee: Xiaobing Zhou
>         Attachments: HIVE-9480.1.patch, HIVE-9480.3.patch, HIVE-9480.4.patch
>
>
> Hive already supports LAST_DAY UDF, in some cases, FIRST_DAY is necessary to 
> do date/timestamp related computation. This JIRA is to track such an 
> implementation. Choose to impl TRUNC, a more standard way to get the first 
> day of a a month, e.g., SELECT TRUNC('2009-01-12', 'MM') FROM src LIMIT 1; 
> will return 2009-01-01
> BTW, this TRUNC is not as feature complete as aligned with Oracle one. 'MM' 
> is the only format supported, however, it's a base to add on other formats.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to