gistfile1.txt

alter table dictionaries_instrumenttype add column default_processing_level_id integer null references dictionaries_processinglevel(id) deferrable initially deferred;
update dictionaries_instrumenttype set default_processing_level_id = base_processing_level_id;
CREATE INDEX "dictionaries_instrumenttype_default_processing_level_id" ON "dictionaries_instrumenttype" ("default_processing_level_id");
ALTER TABLE dictionaries_instrumenttype ALTER COLUMN default_processing_level_id SET NOT NULL;