For the most part I don't think any one would get to excited about dealing with a SQL statement that runs in .3 seconds. Most of us are worried about the statements that run for hours and we tend to focus on them. Which is not necessarily a bad thing. But how many statements on your system fit into this category I'm about to describe?
This statement on a per execution runs in .336 seconds, and does 1,627 Logical IOs. It's a pretty simple 3 way table join. All the predicates are simple equality ones that are ANDed together. The kicker is that this statement was called 5,935 times in a 40 minute window for a total of
9,658,869 LIOs and 275,527 Physical IOs and
didn't return any rows. For this 40 minute trace this statement consumed 69% of the total response time and nearly all the PIOs via Sequential Read events. All this to get back nothing.
Maybe the statement can be optimized to do less work, but the real question is why do this at all? Is there a way to avoid running this statement at all?
It's easy to see why no one would have even looked at this SQL in the conventional tuning type engagement. It's fast, the LIOs per execution aren't necessarily bad either given that the tables involved are rather large. Looking at it from a per execution basis, there isn't much reason to get excited. But when looked at with in the context of a running application, it's easy to see that this statement is doing a lot of work for nothing.