CREATE EXTENSION unaccent;
-- must have a UTF8 database
SELECT getdatabaseencoding();
 getdatabaseencoding 
---------------------
 UTF8
(1 row)

SET client_encoding TO 'KOI8';
SELECT unaccent('foobar');
 unaccent 
----------
 foobar
(1 row)

SELECT unaccent('£ΜΛΑ');
 unaccent 
----------
 ΕΜΛΑ
(1 row)

SELECT unaccent('³φιλ');
 unaccent 
----------
 εφιλ
(1 row)

SELECT unaccent('unaccent', 'foobar');
 unaccent 
----------
 foobar
(1 row)

SELECT unaccent('unaccent', '£ΜΛΑ');
 unaccent 
----------
 ΕΜΛΑ
(1 row)

SELECT unaccent('unaccent', '³φιλ');
 unaccent 
----------
 εφιλ
(1 row)

SELECT ts_lexize('unaccent', 'foobar');
 ts_lexize 
-----------
 
(1 row)

SELECT ts_lexize('unaccent', '£ΜΛΑ');
 ts_lexize 
-----------
 {ΕΜΛΑ}
(1 row)

SELECT ts_lexize('unaccent', '³φιλ');
 ts_lexize 
-----------
 {εφιλ}
(1 row)