HELP INDEX and Hash, Join and Covering Indexes - Advanced SQL Engine

HELP INDEX and Hash, Join and Covering Indexes - Advanced SQL Engine - Teradata Database

SQL Data Definition Language Detailed Topics

Product

Advanced SQL Engine

Teradata Database

Release Number

17.10

Published

July 2021

Language

English (United States)

Last Update

2021-07-27

dita:mapPath

imq1591724555718.ditamap

dita:ditavalPath

imq1591724555718.ditaval

dita:id

B035-1184

lifecycle

Product Category

Teradata Vantage™

HELP INDEX does not report information about hash or join indexes.

HELP INDEX does report on the indexes defined on hash and join indexes, as explained in the following table:

FOR this type of index …	Information is reported on the following index characteristics …
Hash	Primary index defined by default based on the primary index of its underlying table. Primary index defined explicitly by means of the BY and ORDER BY clauses of the CREATE HASH INDEX statement. See Specifying the Primary Index for a Hash Index for information about these primary indexes.
Join	Primary index defined for the join index. Any secondary indexes defined on the join index.

FOR this type of index …

Information is reported on the following index characteristics …

Hash

Primary index defined by default based on the primary index of its underlying table.
Primary index defined explicitly by means of the BY and ORDER BY clauses of the CREATE HASH INDEX statement.

See Specifying the Primary Index for a Hash Index for information about these primary indexes.

Join

Primary index defined for the join index.

Any secondary indexes defined on the join index.

HELP INDEX does not report the ordering columns for a covering index or value-ordered join index. SHOW TABLE reports these columns (see SHOW object).