Caching bunch of simple queries in rails

In my app there're objects, and they belong to countries, regions, cities, types, groups, companies and other sets. Every set is rather simple - it has id, name and sometimes some pointers to other sets, and it never changes. Some sets are small and I load them in before_filter like that:

@countries = Country.all
@regions = Region.all

But then I call, for example, offer.country.name or region.country.name and my app performs a separate db query-by-id, although I've already loaded them all. After that I perform query through :include, and this case ids, generated by eager loading, do not depend on either I've already loaded this data with anoth开发者_JAVA技巧er query-by-id or not.

So I want some cache. For example, I may generate hashes with keys as records-ids in my before_filter and then call @countries[offer.country_id].name. This case it seems I don't need eager loading and it's easy turn on Rails.cache here. But maybe there's some smart built-in rails solution that does not require to rewrite everything?

Caching lists of models like that won't cache individual instances of that exist in other model's associations.

The Rails team has worked on implementing Identity Maps in Rails 3.1 to solve this exact problem, but it is disabled by default for now. You can enable it and see if it works for your problem.