16.20 - PRIMARY KEY - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Data Definition Language Syntax and Examples

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Published
March 2019
Language
English (United States)
Last Update
2019-05-24
dita:mapPath
wkf1512081455740.ditamap
dita:ditavalPath
TD_DBS_16_20_Update1.ditaval

No two rows in the table can have the same value for the defined column set. The system uses a unique primary or secondary index to enforce this constraint.

Only one primary key can be specified per table. To specify candidate primary keys for referential integrity relationships with other tables, use the UNIQUE definition clause.

You cannot specify a PRIMARY KEY constraint for a QITS column (see QITS_column_name).

The system implicitly creates a unique index on any column set specified as PRIMARY KEY if it is not also defined to be the primary index for the table.