Feature Paging

I've just been hand-waving, but Chris Holmes is getting ready to blaze a trail for GeoServer from WFS to restful features. He, more than anyone, has clued me into the significance of paging links for GIS applications, and his post has a good introduction to the concept.

Feature paging should let us reduce the latency in some web GIS applications. Break a huge query response -- and I've seen the GeoServer bloggers mention gigabytes of GML -- into chunks of N (hundreds? thousands?) features, and you can render or analyze chunk i while chunk i+1 is coming through the intertubes.

Paging helps on the server end as well. An intriguing MapServer development proposal to allow XSL transformation of outgoing features was just ditched because WFS doesn't accomodate chunked responses, and it seemed too expensive and slow to build and transform an entire, potentially huge XML document before even beginning to send it. XSLT of reasonably-sized chunks, each with a link to the next, is rather more feasible.

The only thing in Chris's post that I'll dispute is his exaggeration of my credentials. I'm just an HTTP enthusiast, but I do see a huge potential for REST in the geospatial community and I'd like to help realize it.