Rails Query Cache Context Plugin

There is a simple query cache in Rails. When you use find method to query and the query cache is active, the result will be save in a hash with the sql key. But it literally keys cached model instances on the SQL that was used to pull them out of the database, it can't connect multiple find invocations that are phrased differently but have the same semantic meaning and results.

The ActiveRecordContext plugin by Rick Olson is an example of a query cache implementation that is a little bit smarter about identity, since it keys cached results on primary keys rather than SQL statements.

The ActiveRecordContext README:http://svn.techno-weenie.net/projects/plugins/active_record_context/README

Another blog about this Plugin：
http://activereload.net/2007/5/23/spend-less-time-in-the-database-and-more-time-outdoors