Collating

A number of issues regarding collating must be considered when you use InfoSphere® DataStage® with National Language Support (NLS) mode enabled.

Collating is a complex issue for many languages. It is not sufficient to collate a character set in numerical order of its Unicode values. Locales that share a character set often have different collating rules. For example, these are the main issues that affect collating in Western European languages:

• Accented characters. Should accented characters come before or after their unaccented equivalents? Or should accents only be examined if two strings being compared would otherwise be identical (that is, as a tie breaker)?
• Expanding characters. Some languages treat certain single characters as two separate characters for collating purposes.
• Contracting characters. Some languages have pairs of characters that collate as though they were a single character.
• Should case be considered? Should case be used as a tie breaker for otherwise identical strings? If so, which comes first, uppercase or lowercase?
• Should hyphens or other punctuation be considered as tie breakers?