16.10 - About Collation Sequences - Teradata Database

Teradata Database International Character Set Support

prodname
Teradata Database
vrm_release
16.10
created_date
June 2017
category
Configuration
User Guide
featnum
B035-1125-161K

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.