Colin Henderson's Library tagged hueniverse →  View Popular

The retrieval system is where things are not as simple. Unlike webmail services where refreshing a user’s inbox only queries a very simple data set (is there anything new in MY inbox?), refreshing a user’s home page on Twitter queries a much more complex data set (are there any new updates in ALL my friends’ pages?) and the nature of the service means that the ratio of reads to writes is significantly different from most other web services.