Handling Heroku PostgreSQL Dev row limit

Free Heroku PostgreSQL Dev database has row limit: 10,000 rows.
Recently, I got following error in Rails app:
ActiveRecord::StatementInvalid (PG::Error: ERROR: permission denied for relation ...)

I started browsing the Internet and I found this entry at StackOverflow. After checking database:

SELECT schemaname,relname,n_live_tup 
  FROM pg_stat_user_tables 
  ORDER BY n_live_tup DESC;

Truncating tables did a job 🙂

TRUNCATE TABLE name;
TRUNCATE TABLE name CASCADE;