we have 250k products and we want to create more than 200 different site(multi site) all stores will have same products but different domain and different design. Magento multi site function is good for us but you need to match every product and every site so that means 50m(min) record for tables like "catalog_product_website"(and some other tables) and also flat catalog and indexing will be a real problem.
if we use store and store view than userbase will be same and also flat catalog will be problem.
So my question, is there any way to make all these stores work like single store? Or is there any way to make it work with nice performance?