I am planning a WP 3 site running 100,000 sites with visitors and site owners around the world, running Buddypress. Instead of having 10+ tables for each blog, I'd like to have 1 table for all the blogs and add a site_id column to those tables. I know there are pros and cons with this. I also know that th WP developers chose to "shard" the data by splitting each site's data into their own set of tables (http://www.emmanuelgeorjon.com/en/wordpress-mu-la-base-de-donnees-2667/). Is this method indeed "sharding"?
I know I will have to modify some WPMS/MU db code and/or each MU plugin to properly use my modified db schema.
I also know there are several Multi DB plugins out there including multi-db and sharDB which is definitely an option.
Would collapsing/combining/merging mu tables into one be of much use or is it a better idea (performance, manageability, backup, etc) use a multi-db plugin?
Thank you very much!