17.05 - Description of a UNION Operation - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Manipulation Language

Advanced SQL Engine
Teradata Database
Release Number
Release Date
January 2021
Content Type
Programming Reference
Publication ID
English (United States)

Each query connected by UNION is performed to produce a result consisting of a set of rows. The union must include the same number of columns from each table in each SELECT statement (more formally, they must be of the same degree), and the data types of these columns should be compatible. All the result sets are then combined into a single result set that has the data type of the columns specified in the first SELECT statement in the union.