[gefh]

I don't get it. It looks like a spiral. If your query is anywhere other than the center of the space, how is the locality maximized? For a large enough space, didn't this look just like striping rather vertically or horizontally?

[benrbray]

From the abstract, it looks like they're optimizing for rectangular queries instead of single points. For a single point, I think you're right.

> We present the onion curve, an SFC whose clustering performance is provably close to optimal for cube and nearcube shaped query sets

(Edit: But on the other hand this paper has some signs of inexperienced authors, such as this sentence: "A search for applications of space filling curves yields more than a thousand citations on Google Scholar")

[saalweachter]

This is does seem like a trivial optimization over striping.

If your target area is small relative to your potential search space -- imagine your grid is a million by million rows and you are selecting rectangles that are between 10 and 1000 units wide in either dimension -- you'll end up with height or width number of rows or columns to search, most of the time.

Meanwhile, if your target area is large compared to your potential search space ... you also end up with height or width number of L-shaped segments to search along. You only end up with fewer segments if your search area happens to include the center.

Also, not actually a space-filling curve.