pg_collkey is a wrapper to use the collation functions of the ICU library with a PostgreSQL database server. Using this wrapper, you can specify the desired locale for sorting UTF-8 strings directly in the SQL query, rather than setting it during database installation. Default Unicode collation (DUCET) is supported. You can select whether punctuation should be a primary collation attribute or not. The level of comparison can be limited (in order to ignore accents, for example). Numeric sequences of strings can be recognized, so that 'test2' sorts before 'test10'. This library is dependent on ICU.