The following bug has been logged online:
Bug reference: 6230
Logged by: Dmitry Ryabov
Email address: dmitry-ryabov(at)mail(dot)ru
PostgreSQL version: 9.1
Operating system: Windows x64
Description: strange changes in behavior of string functions
Details:
In the version 9.1 I was surprised to find that the function "upper" now is
not working as before. For example:
select upper ('SISTEM AYGıTLARı') = 'SISTEM AYGITLARI'
in postgresql 9.0 returns true, but in postgresql 9.1 - false. Such behavior
now occurs under the transformations of other national symbols. In the
release notes that I have not found mention of such changes. Question: is
the bug? Sorry for my bad English.