BEGIN;

DROP TABLE language_names;

ALTER TABLE languages ADD COLUMN english_name VARCHAR;
ALTER TABLE languages ADD COLUMN self_name    VARCHAR;

ALTER TABLE languages ADD CONSTRAINT english_name_is_sane_text
    CHECK (english_name IS NULL OR is_sane_text(english_name));
ALTER TABLE languages ADD CONSTRAINT self_name_is_sane_text
    CHECK (self_name    IS NULL OR is_sane_text(self_name));

CREATE UNIQUE INDEX languages_english_name ON languages (english_name);

COMMIT;