16.20 - Join Indexes and Base Tables - 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 join index is similar to a base table. For example, you can do the following things to a join index:

  • Create nonunique secondary indexes on its columns.
  • Create a unique primary index on its columns, provided it is a non-compressed and nonvalue-ordered single-table join index.
  • Execute COLLECT STATISTICS, DROP STATISTICS, HELP, and SHOW statements.
  • Partition its primary index, if it is a noncompressed join index.

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

  • Query or update join index rows explicitly.
  • Store and maintain arbitrary query results such as expressions.
    You can maintain aggregates or sparse indexes if you define the join index to do so.