DB-Level “no overlapping ranges” with exclusion constraint

                  class PreventOverlappingBookings < ActiveRecord::Migration[6.1]
  def change
    enable_extension 'btree_gist'

    execute <<~SQL
      ALTER TABLE bookings
      ADD CONSTRAINT no_overlapping_bookings
      EXCLUDE USING gist (
        room_id WITH =,
        tstzrange(starts_at, ends_at) WITH &&
      );
    SQL
  end
end