Yeah, know your data and how it is used. I assume that data access is mostly linear because of a few reasons:

1. All performance issues arise in loops: I at least have never seen a performance problem that could be explained by a single thing happening once. It is always a particular thing happening over and over again.

2. All loops deal with collections of data, and the collections are usually created either created manually by a human being, or are created through parsing or looping many at a time.

3. A human being can manually create a collection of maybe a hundred items manually before they get bored and stop. A collection created this way may contain data from all over the place, with data access over it being nonlinear.

4. A collection created through parsing or looping will create its data in a mostly linear fashion. Accessing the data will then also be linear.

There are definitely cases where nonlinear collections exist, but these are usually either small or are created from smaller sets of linear data. eg. Think of dragging 10 lists of 1000 items to form a list of 10000 items. The entire 10000 items aren't going to be located linearly, but every 1000 items will be.

So in effect, I'm betting that most hot loops do deal with linear access over objects and that loops that work over nonlinear access are not particularly hot.

Makes sense when you put it like that, thanks very much for explaining your thought process.