[DERBY-4627] Document how to install your own custom collation for use in sorting and comparing string data values.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.6.1.0
• Fix Version/s: 10.10.2.0, 10.11.1.1
• Component/s: Documentation
• Issue & fix info: High Value Fix
• Assignee: Camilla Haase
• Reporter: Richard N. Hillegas
• Created: 23/Apr/10 16:03
• Updated: 16/Apr/14 02:41
• Resolved: 29/Aug/13 17:27

Description

The Developer's Guide suggests that you are limited to the collations shipped with the JRE. Consider, for instance, this sentence in the section titled "Character-based collation in Derby":

"Derby currently supports only running those rules that can be loaded dynamically from the running JVM based on the territory attribute. Overrides to these rules by the user are not supported."

This is misleading. A long time ago, Knut wrote a blog explaining how to write your own custom collation, plug it into the JRE, and then use it on string data stored in Derby: http://blogs.sun.com/kah/entry/user_defined_collation_in_apache

This is a very useful capability of Derby. We should document it.