16.20 - Queries Using a Hash Index - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantageâ„¢ SQL Fundamentals

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Published
March 2019
Language
English (United States)
Last Update
2019-05-02
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In most respects, a hash index is similar to a base table. For example, you can perform COLLECT STATISTICS, DROP STATISTICS, HELP, and SHOW statements on a hash index.

Unlike base tables, you cannot do the following things with hash indexes:

  • Query or update hash index rows explicitly.
  • Store and maintain arbitrary query results such as expressions.
  • Create explicit unique indexes on its columns.
  • Partition the primary index of the hash index.