How granular is the data that folks are typically putting into memcached?
Use your imagination and make it work best for you. The nice thing about memcached is that it gives you the freedom to do what you want... as long as it is less than 1MB.
The last consideration I'm thinking through in all of this is how to manage serializable class versioning.
My technique. http://www.socialtext.net/memcached/index.cgi?faq#simulating_namespaces_with_key_prefixes
-- Brian Moon Senior Developer ------------------------------ When you care enough to spend the very least. http://dealnews.com/
