Which type of Primary Index would you use to avoid duplicate values in Teradata?

Using a Unique Primary Index in Teradata is critical for ensuring that there are no duplicate values allowed in a specified column or columns of a table. When you define a Unique Primary Index on a table, Teradata enforces uniqueness by preventing duplicate values from being inserted into the indexed column(s). If an attempt is made to insert a duplicate value, Teradata will return an error and reject the operation, maintaining the integrity of the data.

This type of index is particularly useful in scenarios where you need to uniquely identify rows in a table, such as with user IDs or account numbers, where each entry must be distinct. It acts as a constraint that helps uphold the relational database principles of data accuracy and reliability.

In contrast, a Nonunique Primary Index allows for duplicate values, which means that while it can be used for distributing data across the AMPs (Access Module Processors) more evenly, it does not enforce uniqueness and therefore does not prevent duplicates. Secondary indexes are also used to speed up data retrieval but do not play a role in enforcing uniqueness. Similarly, a Global Temporary Index provides an index structure that exists only for the duration of a user session and is not designed for enforcing uniqueness across a dataset. Thus, to prevent duplicate values, the Unique