T.Ashish (9/18/2013)
Grant,What I have learn is, we have a "estimated plan" and a "actual plan". When we execute a query, SQL gives us the actual plan of what it had to do, to give us the results.
But in your blog you are saying "the actual plan costs are still just estimates".
So, why SQL is not able to give us the exact costing of what it has done !!!!
The "actual" plan is just an estimated plan with a few run-time metrics including things like: number of actual executions, actual rows returned, actual rebinds, actual rewinds, a couple of others. SQL Server doesn't measure the internals of the operations on each and every execution of a query. That would just be too costly.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning