17.05 - Anchored Interval Uses System-defined Business Calendar Set in the Session - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Manipulation Language

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Release Date
January 2021
Content Type
Programming Reference
Publication ID
B035-1146-175K
Language
English (United States)

Vantage uses a system-defined business calendar set in the session for the anchored interval in an EXPAND ON clause.

In an anchor expansion, Vantage derives the BEGIN bound of the first expanded row from the business calendar set in the current session. The BEGIN bound of the first expanded row is derived from the YearBeginDate, WeekStart, and CalendarPeriod columns from the BusinessCalendarPattern table.

For example, a row has period from 1-Jan-2008 to 31-May-2008, YearBeginDate is 15-Mar-2008, and CalendarPeriod is from 1-Jan-08 to 30-Oct-08. Expanding by anchor point MONTH_BEGIN results in 4 rows, where the first row is from 15-Jan-08 to 15-Feb-08 and second row is from 15-Feb-08 to 15-Mar-08 and third row is from 15-Mar-08 to 15-Apr-08 and the forth row is from 15-Apr-08 to 15-May-08. The MONTH_BEGIN value is derived from the YearBeginDate value, which is January 15 and, because the Calendar begins in January, the first month starts on January 15.