Michael Ross (8/24/2009)
Rerunning queries multiple times and clearing the cache? Is that REALLY necessary every time? That just leads me to believe that the developer really doesn't know what they are doing, and they are merely hunting and pecking towards a faster result with little regard for data accuracy.
Once you run the query once, all the relevant indexes are likely to be in memory in SQL Server's cache, and every subsequent query may come back in 0.1 seconds, which will totally mask the problem that the first time you run the query it may take 5 seconds to run. It will also completely mask any significant changes in performance you get as a result of changing the query. It is really necessary to do that every time.