16.20 - nPath Symbols - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ - NewSQL Engine Analytic Functions

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Release Date
July 2019
Content Type
Programming Reference
Publication ID
B035-1206-162K
Language
English (United States)

A symbol identifies a row in the Pattern and Result syntax elements. A symbol can be any valid identifier (that is, a sequence of characters and digits that begins with a character) but is typically one or two uppercase letters. Symbols are case-insensitive; that is, 'SU' is identical to 'su', and the system reports an error if you use both.

For example, suppose that you have this input table:

record city temp rh cloudcover windspeed winddirection rained_next_day
1   81 30 0.0 5 NW 1
2 Tempe 76 40 0.2 15 NE 0
3   70 70 0.4 10 N 0
4 Tusayan 75 50 0.4 5 NW 0

This table has examples of symbol definitions and the rows of the table that they match in NONOVERLAPPING mode:

Symbol Definition Rows Matched
temp >= 80 AS H 1
winddirection = 'NW' AS NW 1, 4
winddirection = 'NW' OR windspeed > 12 AS W 1, 2, 4
cloudcover <> 0.0 AND rh > 35 AS C 2, 3, 4
TRUE AS A 1, 2, 3, 4

This symbol definition matches all rows, for any input table.

city like 'tu%' AS TU The like operator depends on Teradata Session mode:
Mode Match
BTET 1, 3, 4
ANSI None
city not like 'tu%' AS TU 2
city not like 'Tu%' AS N 2
city like 'Tu%n' as T 1, 3, 4

The % operator matches any number of characters.

city like 'Tu___n' as T 1, 3

The underscore (_) operator matches any single character. The pattern 'Tu___n' has three underscores, so it matches 'Tucson' but not 'Tusayan'.

Rows with NULL values do not match any symbol. That is, the function ignores rows with missing values.