Here's small patch to fix case conversion problems for ILIKE and
(Oracle Compat.) lower/upper functions. (Related bug report is here:
http://archives.postgresql.org/pgsql-bugs/2005-10/msg00001.php)
In tests it succeeded for Turkish characters while using LATIN5
encoding. But when encoding is UNICODE it still doesn't work. (IMHO,
for latin-N encodings there will be no compatibility problems; for
Unicode, I've no idea.)
Regards.