I was recently setting up a SQL membership provider with ASP.Net, and was curious as to how the User ID's were being generated. Typically if a database table is going to have a large number of rows, you don't want to use NewID() to populate a GUID (aka UniqueIdentifier) primary key. The problem is noted in the much-referenced article by Jimmy Nilsson where he basically came up with the GUID.Comb to address this. This is now used by NHibernate to solve the issue of inefficiency of SQL Server GUID PK operations.
SQL Server 2005 attempts to address this issue through...