17.10 - Value-Ordered NUSIs - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - SQL Fundamentals

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1141-171K
Language
English (United States)

Value-ordered NUSIs are very efficient for range conditions, and more so when strongly selective or when combined with covering. Because the NUSI rows are sorted by data value, it is possible to search only a portion of the index subtable for a given range of key values.

Value-ordered NUSIs have the following limitations.

  • The sort key is limited to a single numeric or DATE column.
  • The sort key column must be four or fewer bytes.

The following query is an example of the sort of SELECT statement for which value-ordered NUSIs were designed.

   SELECT *
   FROM Orders
   WHERE o_date BETWEEN DATE '1998-10-01' AND DATE '1998-10-07';