Hi!
Weeeeellll, we _could_ add indexable summary fields, and update them lazily in the background when required.
Still means a database layout change to the revision table, which might be a little expensive on upgrade.
It can be a task for tool server, and can be as well derived from our xml dumps.
We have all that information in recentchanges (without an index for this exact operation), but even then, I'm not convinced it has to be used his way.
What is the point of per-namespace contribution feature on live site? What are the applications of it?
Domas