[rix0r]

For index-seeks, yes.

For key-seeks, it's a normal tree walk to the leaf (unless an INSERT is found at a higher level, iirc)

In practice, the blocks are so huge that any tree is going to have at most depth 3, and the root page is likely in cache, so 1 or 2 s3 fetches (= roughly 200ms, let's say)

I've been toying with the idea of putting the root page (or maybe the top 2 levels of pages) in DynamoDB, which would make them fast even if they weren't in cache.