16.20 - Usage Notes - Teradata Vantage NewSQL Engine

Teradata Vantageā„¢ SQL Functions, Expressions, and Predicates

prodname
Teradata Database
Teradata Vantage NewSQL Engine
vrm_release
16.20
category
Programming Reference
featnum
B035-1145-162K

FIRST_VALUE and LAST_VALUE are especially valuable because they are often used as the baselines in calculations. For instance, with a partition holding sales data ordered by day, you may want to know how much the sales for each day were compared to the first sales day (FIRST_VALUE) for the period, or you may want to know, for a set of rows in increasing sales order, what the percentage size of each sale in the region was compared to the largest sale (LAST_VALUE) in the region.

IGNORE NULLS is particularly useful in populating an inventory table properly.

Selecting neither IGNORE NULLS or RESPECT NULLS is equivalent to selecting RESPECT NULLS.