- 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.initial.sql

@@ -37,7 +37,7 @@ CREATE INDEX users_alias_id_idx ON users (alias);
 --
 
 CREATE TABLE "session" (
-    sess_id varchar(40) DEFAULT '' PRIMARY KEY,
+    sess_id varchar(128) DEFAULT '' PRIMARY KEY,
     created timestamp with time zone DEFAULT now() NOT NULL,
     changed timestamp with time zone DEFAULT now() NOT NULL,
     ip varchar(41) NOT NULL,