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

International Character Set Support

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Published
July 2021
Language
English (United States)
Last Update
2021-07-28
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B035-1125
lifecycle
previous
Product Category
Teradata Vantage™

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.