Usage Notes - Analytics Database - Teradata Vantage

SQL Functions, Expressions, and Predicates

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2024-01-12
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lifecycle
latest
Product Category
Teradata Vantageā„¢

CURRENT_TIME returns the current time when the request started. If CURRENT_TIME is invoked more than once during the request, the same time is returned. The time returned does not change during the duration of the request.

If you specify CURRENT_TIME without the AT clause or CURRENT_TIME AT LOCAL, then the value returned depends on the setting of the DBS Control flag TimeDateWZControl as follows:
  • If the TimeDateWZControl flag is enabled, CURRENT_TIME returns a time constructed from the session time and session time zone.
  • If the TimeDateWZControl flag is disabled, CURRENT_TIME returns a time constructed from the time value local to Vantage and the session time zone.
The following occurs when using CURRENT_TIME with daylight saving time (DST):
  • When TimeDateWZControl flag is enabled and the session time zone is defined with a time zone string that follows different Daylight Saving Time and standard time zone displacements, then CURRENT_TIME AT LOCAL gives TIME value corresponding to Standard time zone rather than the Daylight Saving Time time zone.
  • During the Daylight Saving Time period, CURRENT_TIME AT LOCAL follows Standard time zone, whereas CURRENT_TIME follows the Daylight Saving Time zone. During Standard time zone period, both CURRENT_TIME and CURRENT_TIME AT LOCAL follow the standard time zone.

For example, during DST period:

BTEQ -- Enter your SQL request or BTEQ command: 
.os date       
Sat Sep  5 14:00:23 PDT 2015

BTEQ -- Enter your SQL request or BTEQ command: 
.os date -u
Sat Sep  5 21:00:26 UTC 2015

BTEQ -- Enter your SQL request or BTEQ command: 
select current_time, current_time at local;


*** Query completed. One row found. 2 columns returned. 
 *** Total elapsed time was 1 second.

Current Time(0)  Current Time(0) AT LOCAL
---------------  ------------------------
14:00:30-07:00            13:00:30-08:00

During Standard Time Zone Period:

BTEQ -- Enter your SQL request or BTEQ command: 
.os date
Fri Nov  6 04:18:04 PST 2015

BTEQ -- Enter your SQL request or BTEQ command: 
.os date -u
Fri Nov  6 12:18:07 UTC 2015

BTEQ -- Enter your SQL request or BTEQ command: 
select current_time, current_time at local;


*** Query completed. One row found. 2 columns returned. 
 *** Total elapsed time was 1 second.

Current Time(0)  Current Time(0) AT LOCAL
---------------  ------------------------
04:18:20-08:00            04:18:20-08:00
If CURRENT_TIME is used in a stored procedure, the procedure must be recompiled whenever the DBS Control fields System TimeZone Hour or System TimeZone Minute are changed. Recompiling stored procedures is not necessary if a time zone string is set using the tdlocaledef utility.