- Useful for locating rows having a specific value in the index.
- Can be hash-ordered or value-ordered.
Value-ordered NUSIs are particularly useful for enhancing the performance of range queries.
- Any access is an all-AMPs operation with the exception of the case where a NUSI is defined on the same column set as the primary index for the table.
- An index defined with an ORDER BY clause counts as 2 consecutive indexes against the table limit of 32 secondary and join indexes (see Importance of Consecutive Indexes for Value-Ordered NUSIs).