17.10 - Classic Indexes and Teradata Indexes - 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)
The classic index for a relational database is itself a file made up of rows having these parts:
  • A (possibly unique) data field in the referenced table.
  • A pointer to the location of that row in the base table (if the index is unique) or a pointer to all possible locations of rows with that data field value (if the index is nonunique).

Because Vantage is a massively parallel architecture, it requires a more efficient means of distributing and retrieving its data. One such method is hashing. All Teradata indexes are based on row hash values rather than raw table column values, even though secondary, hash, and join indexes can be stored in order of their values to make them more useful for satisfying range conditions.