Session Modes in Teradata

Teradata session modes description

The Teradata database has different modes for running queries: ANSI Mode (rules based on the ANSI SQL: 2011 specifications) and TERA mode (rules defined by Teradata). Please review the following Teradata documentation for more information.

Teradata mode for strings informative table

For strings, the Teradata Mode works differently. As it is explained in the following table based on the Teradata documentation:

Feature	ANSI mode	Teradata mode
Default attribute for character comparisons	CASESPECIFIC	NOT CASESPECIFIC
Default TRIM behavior	TRIM(BOTH FROM)	TRIM(BOTH FROM)

Translation specification summary

Mode	Column constraint values	Teradata behavior	SC expected behavior
ANSI Mode	CASESPECIFIC	CASESPECIFIC	No constraint added.
	NOT CASESPECIFIC	CASESPECIFIC	Add COLLATE 'en-cs' in column definition.
Teradata Mode	CASESPECIFIC	CASESPECIFIC	In most cases, do not add COLLATE, and convert its usages of string comparison to RTRIM( expression )
	NOT CASESPECIFIC	NOT CASESPECIFIC	In most cases, do not add COLLATE, and convert its usages of string comparison to RTRIM(UPPER( expression ))

Available translation specification options

• TERA Mode For Strings Comparison - NO COLLATE

• TERA Mode For Strings Comparison - COLLATE

• ANSI Mode For Strings Comparison - NO COLLATE

• ANSI Mode For Strings Comparison - COLLATE