Mailing-List: contact issues-help@hive.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@hive.apache.org
Date: Fri, 27 Oct 2017 00:26:04 +0000 (UTC)
From: "Jesus Camacho Rodriguez (JIRA)" <jira@apache.org>
To: issues@hive.apache.org
Message-ID: <JIRA.12905321.1444942066000.74605.1509063964081@Atlassian.JIRA>
In-Reply-To: <JIRA.12905321.1444942066000@Atlassian.JIRA>
References: <JIRA.12905321.1444942066000@Atlassian.JIRA> <JIRA.12905321.1444942066345@jira-lw-us.apache.org>
Subject: [jira] [Assigned] (HIVE-12192) Hive should carry out timestamp
 computations in UTC
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
archived-at: Fri, 27 Oct 2017 00:26:11 -0000


     [ https://issues.apache.org/jira/browse/HIVE-12192?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jesus Camacho Rodriguez reassigned HIVE-12192:
----------------------------------------------

    Assignee: Jesus Camacho Rodriguez

> Hive should carry out timestamp computations in UTC
> ---------------------------------------------------
>
>                 Key: HIVE-12192
>                 URL: https://issues.apache.org/jira/browse/HIVE-12192
>             Project: Hive
>          Issue Type: Sub-task
>          Components: Hive
>            Reporter: Ryan Blue
>            Assignee: Jesus Camacho Rodriguez
>              Labels: timestamp
>
> Hive currently uses the "local" time of a java.sql.Timestamp to represent the SQL data type TIMESTAMP WITHOUT TIME ZONE. The purpose is to be able to use {{Timestamp#getYear()}} and similar methods to implement SQL functions like {{year}}.
> When the SQL session's time zone is a DST zone, such as America/Los_Angeles that alternates between PST and PDT, there are times that cannot be represented because the effective zone skips them.
> {code}
> hive> select TIMESTAMP '2015-03-08 02:10:00.101';
> 2015-03-08 03:10:00.101
> {code}
> Using UTC instead of the SQL session time zone as the underlying zone for a java.sql.Timestamp avoids this bug, while still returning correct values for {{getYear}} etc. Using UTC as the convenience representation (timestamp without time zone has no real zone) would make timestamp calculations more consistent and avoid similar problems in the future.
> Notably, this would break the {{unix_timestamp}} UDF that specifies the result is with respect to ["the default timezone and default locale"|https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF#LanguageManualUDF-DateFunctions]. That function would need to be updated to use the {{System.getProperty("user.timezone")}} zone.


--
This message was sent by Atlassian JIRA
(v6.4.14#64029)