Is this expensive Clustered index seek good or bad? If not how could I improve it

Wayne1973 2014-12-04 17:40:57

SQLkiwi 2014-12-09 10:41:47
The whole query runs in 2ms, so it's hard to say if anything is "bad". The estimated cost of the Table3 seek is 75% of the cost, but remember these costs are all estimates calculated using an abstract model – they don't necessarily correlate with real runtime costs. A second point is that percentages can be misleading; unless all the operations in a plan have similar cost, there will always be something with a higher percentage cost than the others.

In terms of the plan itself, one thing worth mentioning is that each of the seeks has a residual predicate (a test applied to rows that meet the seek criteria). If these predicates can be incorporated into the index keys instead, you might find an improvement. Not that there's much improvement to look for in a 2ms execution, but the general point is valid.