Have you ever wanted to do some hard-core database tuning or query tuning on a SQL Server database, but the database was just too large. I can recall plenty of situations where I was tuning SQL queries and stored procedures that ran blisteringly fast in the development environment. But once the SQL and Transact-SQL code was deployed to production, the code slowed down as the database grew in size from thousands to millions of records.
Joe Chang, a brilliant independent consultant and former Intel product manager, has developed a utility called SQL Clone that duplicates the operational behavior of potentially huge databases while still keeping the actual size very small. This is possible by reproducing the schema of the database and retaining the statistics of the very large database. This fools SQL Server into using query behavior that is like what you'd get from the big database.
Read more about it at http://www.sql-server-performance.com/news_releases/joechang_20060228.asp.
If you have to support large and very large databases, then you owe it to yourself to download and start using SQL Clone.