- Fixed bug where session ID's length was limited to 40 characters. Since PHP5.3 it's possible

to set session.hash_function to any hash algorithm that would produce strings
  up to 128 characters long (#1488196)

SQL/postgres.update.sql

@@ -165,3 +165,5 @@ CREATE TABLE cache_messages (
 );
 
 CREATE INDEX cache_messages_changed_idx ON cache_messages (changed);
+
+ALTER TABLE "session" ALTER sess_id TYPE varchar(128);