How to speed up a SQL Server query involving count(distinct())?

Create an index on url which would cover the GUID.

Scaning indexes that large will take long no matter what. What you need to do is to shorten the indexes. What you can do is have an integer column where the checksum of the url is calculated and stored.

This way your index will be narrow and count will be fast.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.