16.20 - About Collation Sequences - Teradata Vantage NewSQL Engine

Teradata Vantage™ NewSQL Engine International Character Set Support

Teradata Database
Teradata Vantage NewSQL Engine
March 2019
User Guide

Collations control character ordering and comparison operations during Teradata Database 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.