What is the function of a Secondary Index in Teradata?

A Secondary Index in Teradata serves to create an alternate access path to data within a table, which allows users to efficiently retrieve rows without having to resort solely to the primary index path. By providing this alternative route, the Secondary Index not only enhances the speed of querying but also enforces constraints that can ensure data uniqueness when necessary. This capability allows for faster searches and retrieval operations on columns that are not part of the primary index, thereby improving overall query performance.

The other options do not accurately describe the function of a Secondary Index. For instance, the distribution of data across AMPs relates to how Primary Indexes function to balance workload in Teradata. Storing data temporarily is more aligned with the operations of volatile tables or temporary tables rather than Secondary Indexes. Creating join paths pertains more to relationship establishment between tables through Primary and Foreign Keys than to the role of Secondary Indexes.