Inside DBCC CHECKDB... How does it work?
Paul Randal has been writing an excellent series on how DBCC CHECKDB works within SQL Server.
Explaining how SQL Server 2000 and 2005 present a consistent view of the data for checking and why that is important. Paul moves onto what CHECKDB really does and then Checking Database Consistency in Very Large Databases (VLDB).
Paul Randal worked as the Lead Developer / Manager for a team working on the SQL Server Storage Engine responsible for DBCC.