Why did you decide to only split the page into two parts?

I was expecting we'd split the page into N parts, one of which is the original from-disk page items, if any, the other N-1 which are chunks of the skip-list.

Thinking about your approach, it seems to me what you've done is simpler than my approach, and I don't see any reason it won't be as effective, assuming no thread of control is hanging on to a row in the original page.  Is there any reason to believe the big chunk you create won't be evicted relatively soon, vs. a lot of smaller chunks, some of which could be evicted relatively soon, even if all of them can't be?

Anyway, I'd like to hear your rationale for going in this direction vs. creating more, smaller pages, or, did you never plan on creating more than 1 new page?