A data type that has two DateTime elements associated with it.
| The DateTime element... | Specifies... |
|---|---|
| beginning | the beginning bound of a period. |
| ending | the ending bound of a period. |
The beginning bound is inclusive, and the ending bound is exclusive; that is, the DateTime range starts at the beginning bound and extends up to but not including the ending bound.
A PERIOD(TIME[(n)] WITH TIME ZONE) column records the beginning and ending bounds in UTC form in the same manner as exists currently for a TIME WITH TIME ZONE column.
Syntax
PERIOD(TIME [ ( fractional_seconds_precision ) ] WITH TIME ZONE ) [ attribute [...] ]
- fractional_seconds_precision
- A single digit representing the number of significant digits in the fractional portion of the SECOND field.
- attributes
- Appropriate data type, column storage, or column constraint attributes. See Core Data Type Attributes and Storage and Constraint Attributes for specific information.
ANSI Compliance
Period types are a Teradata extension to the ANSI SQL:2011 standard.
Storage
A PERIOD(TIME[(n)] WITH TIME ZONE) is a fixed length data type and is saved as two TIME WITH TIME ZONE values.
| Element Type | Field Size in Bytes | Maximum Size in Bytes in the Row |
|---|---|---|
| TIME(n) WITH TIME ZONE | 16 | 16 |
External Representation of PERIOD(TIME WITH TIME ZONE)
In field mode, Teradata Database returns PERIOD(TIME WITH TIME ZONE) data as character data.
Assume L is the maximum length of the formatted character string for the format associated with this Period data type. The resulting character string contains two strings representing the beginning and ending bounds of the period value expression, each up to length L , and each enclosed in apostrophes ('), separated by comma and a space (,), and then enclosed within a left and right parenthesis [( )]. Thus, the maximum length of the resulting character string is 2* L +8.
- Second: 4-byte, signed integer flipped to client form. This integer represents the number of seconds as a scaled decimal (for example, 12.56 seconds is returned as 12560000).
- Hour: 1 unsigned byte. This byte represents the number of hours.
- Minute: 1 unsigned byte. This byte represents the number of minutes.
- Time Zone Hour: 1 unsigned byte. This byte represents the hours portion of the time zone displacement along with whether the displacement is + or -. A value of 16 represents 0 hours. A value less than 16 represents a negative time zone displacement for the specified hours; that is, if this is 10, the time zone is displaced by -10 hours. If greater than 16, it specifies a positive time zone displacement of (Time Zone Hour - 16) hours; that is, a value of 20 implies a +4 hour displacement.
- Time Zone Minute: 1 unsigned byte. This byte represents the minute's portion of the time zone displacement.
Restrictions
A primary index column or partitioning column cannot be a column that has a Period data type.
Example: PERIOD(TIME WITH TIME ZONE) Data Type
The following CREATE TABLE statement defines a PERIOD(TIME(6) WITH TIME ZONE) column since the precision defaults to 6.
CREATE TABLE t8 ( job_id INTEGER, job_desc CHARACTER(15), job_status CHARACTER(1), job_hours PERIOD(TIME WITH TIME ZONE));
Related Topics
For information on functions and operators that apply to Period types, see Teradata Vantage™ - SQL Functions, Expressions, and Predicates, B035-1145.