15.00 - Unique and Nonunique Primary Indexes - Teradata Database

Teradata Database Design

prodname
Teradata Database
vrm_release
15.00
category
User Guide
featnum
B035-1094-015K

Unique and Nonunique Primary Indexes

You can define a primary index to be either unique or non‑unique. The choice of the columns to use for the primary index may depend on how its rows are most frequently accessed. The uniqueness of a primary index depends on the whether or not the data in the columns is unique.

This topic describes the differences between the two types as well as their relative advantages and disadvantages.