Collation Sequences | International Character Set Support | Teradata Vantage - 17.20 - Collation Sequences - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - Advanced SQL Engine International Character Set Support

Advanced SQL Engine
Teradata Database
Release Number
June 2022
Last Update
Content Type
User Guide
Publication ID
English (United States)

Collations control character ordering and comparison operations during Vantage sessions.

Collations are designed as single level or two level. A two-level collation orders character strings according to a two-level comparison.

Characters are first partitioned into equivalence classes that have the same collating value. The relative ordering of classes and characters within a class is significant.

Comparisons obey the following rules:
  • All characters in a class have the same collation value.
  • A character from class i is less than any character from class i+1.

The process is as follows:

  1. Convert characters in the strings to be compared into equivalence classes.
  2. Compare the strings.
    IF the strings are… THEN processing …
    not equal stops.
    equal continues.
  3. Order characters within each class using criteria defined for the collation sequence, and compare.

The MULTINATIONAL Norwegian standard collation sequence is an example of a two-level collation.