[HIVE-16614] Support "set local time zone" statement

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0
• Labels: TODOC3.0
• Assignee: Jesús Camacho Rodríguez
• Reporter: Carter Shanklin
• Created: 09/May/17 13:32
• Updated: 27/Feb/24 22:23
• Resolved: 24/Aug/17 21:40

Description

HIVE-14412 introduces a timezone-aware timestamp.

SQL has a concept of default time zone displacements, which are transparently applied when converting between timezone-unaware types and timezone-aware types and, in Hive's case, are also used to shift a timezone aware type to a different time zone, depending on configuration.

SQL also provides that the default time zone displacement be settable at a session level, so that clients can access a database simultaneously from different time zones and see time values in their own time zone.

Currently the time zone displacement is fixed and is set based on the system time zone where the Hive client runs (HiveServer2 or Hive CLI). It will be more convenient for users if they have the ability to set their time zone of choice.

SQL defines "set time zone" with 2 ways of specifying the time zone, first using an interval and second using the special keyword LOCAL.

Examples:
• set time zone '-8:00';
• set time zone LOCAL;

LOCAL means to set the current default time zone displacement to the session's original default time zone displacement.

Reference: SQL:2011 section 19.4

Issue Links

• depends upon: HIVE-14412 Add timestamp with time zone
• relates to: HIVE-12192 Hive should carry out timestamp computations in UTC
• relates to: HIVE-20007 Hive should carry out timestamp computations in UTC
• links to: RB link

Sub-Tasks

• Provide smooth migration path for CTAS when time column is not with timezone: Resolved