-- changes id to serial type, starting with next-to-last value 
-- WHICH HAS TO BE ADDED IN BY HAND (last SerNr from table + 1):
DROP SEQUENCE IF EXISTS ori_test_SerNr_seq;
CREATE SEQUENCE	ori_test_SerNr_seq;
ALTER TABLE ori_test ALTER COLUMN SerNr SET DEFAULT nextval('ori_test_SerNr_seq');
ALTER SEQUENCE ori_test_SerNr_seq OWNED BY ori_test.SerNr;
ALTER SEQUENCE ori_test_SerNr_seq RESTART WITH 1300; -- no easy way for user variables in PostgreSQL
