Collation Sequences | International Character Set Support | VantageCloud Lake - Collation Sequences - Teradata Vantage

Teradata® VantageCloud Lake
Deployment
VantageCloud
Edition
Lake
Product
Teradata Vantage
Published
January 2023
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en-US
ft:lastEdition
2024-12-11
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phg1621910019905

Collations control character ordering and comparison operations during VantageCloud Lake 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 equal, processing continues. If not, processing stops.

  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.

Setting and Changing Collations

Collation can be set or changed in the following ways:
  • At the user-definition level with the CREATE USER or MODIFY USER statements.
  • At the session level with the SQL SET SESSION COLLATION statement.

HELP SESSION Statement

Use the HELP SESSION statement to display the collation in effect for your session.

Further Collation Sequences and Character Mappings

Selected collation and character mapping tables are described in text files that are available for download. See Character Set Files.