text: -- 1 up
  CREATE TABLE IF NOT EXISTS lstu (
      short text PRIMARY KEY,
      url text,
      counter integer default 0,
      timestamp integer
  );
  CREATE TABLE IF NOT EXISTS sessions (
      token text PRIMARY KEY,
      until integer
  );
  CREATE TABLE IF NOT EXISTS ban (
      ip text PRIMARY KEY,
      until integer,
      strike integer
  );
  -- 1 down
  DROP TABLE ban;
  DROP TABLE sessions;
  DROP TABLE lstu;
  -- 2 up
  CREATE INDEX IF NOT EXISTS empty_short_idx ON lstu (short) WHERE url IS NULL;
  -- 2 down
  DROP INDEX empty_short_idx;
  -- 3 up
  ALTER TABLE lstu ADD COLUMN created_by text;
  -- 3 down
  ALTER TABLE lstu DROP COLUMN created_by;
  