SQL Server uses high CPU when searching inside nvarchar strings

Question

Check out the following example. It shows that searching within a unicode string (nvarchar) is almost eight times as bad as searching within a varchar string. And on par wit

Answer 1

My guess is that LIKE is implemented using an O(n^2) algorithm as opposed to an O(n) algorithm; it would probably have to be for the leading % to work. Since the Unicode string is twice as long, that seems consistent with your numbers.