I added a bunch of sub-blogs to my network and now certain items are slow to load on the backend. And seeing that domain mapping is running a bunch of queries for no reason. And I'm not sure why if its something I did or something on your end. I see the following queries:
That's just the top three, there are a lot of queries. Now if you don't have many blogs running...you don't notice the overhead but if you do...then it's a problem. I think it shouldn't be querying the whole network of other blog domain mapping data on admin page loads. It's inefficient coding. Please check.