A column or set of columns defined as PRIMARY KEY must also be NOT NULL.
Teradata Database instantiates a PRIMARY KEY as a unique primary or secondary index.
Only one PRIMARY KEY can be defined for a table.
For more details, see:
- “CREATE TABLE” in Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144
- “Keys” in Teradata Vantage™ - SQL Fundamentals, B035-1141
- “Constraint Specifications” in Teradata Vantage™ - Database Design, B035-1094.