title: Mysql::Error: Specified key was too long; max key length is 767 bytes: CREATE INDEX
body: <p>I'm working with rails 2.3.5 application, in witch I have this field</p>
  
  <pre><code>t.string   "trip_cities",             :limit =&gt; 256
  </code></pre>
  
  <p>And this index</p>
  
  <pre><code>add_index "bookings", ["trip_cities"], :name =&gt; "trip_cities"
  </code></pre>
  
  <p>When I try to execute:</p>
  
  <pre><code>bundle exec rake db:test:load
  </code></pre>
  
  <p>I receive this error <code>Mysql::Error: Specified key was too long; max key length is 767 bytes: CREATE  INDEX 'trip_cities' ON 'bookings' ('trip_cities')</code> and don't quite know how to resolve this.</p>