DISTINCT Option | SQL SELECT Statements | Teradata Vantage - 17.05 - DISTINCT - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Manipulation Language

Product
Advanced SQL Engine
Teradata Database
Release Number
17.05
Release Date
January 2021
Content Type
Programming Reference
Publication ID
B035-1146-175K
Language
English (United States)

DISTINCT specifies that duplicate values are not to be returned when an expression is processed.

Only one row is to be returned from any set of duplicates that might result from a given expression list. Rows are duplicates only if each value in one is equal to the corresponding value in the other.

If you specify DISTINCT and an expand_alias in the select list, the database performs the DISTINCT operation after the EXPAND operation to ensure that duplicate rows are removed from the expanded result.

If you specify DISTINCT but do not specify an expand_alias in the select list, the system ignores the EXPAND ON clause (even if you specify one), and does not expand rows.

You cannot specify DISTINCT if any member of the select column list is a LOB column.

ANSI Compliance

DISTINCT is ANSI SQL:2011-compliant.