I just dug my book out. Chapter six shows a custom sort that implements a SortComparatorSource combined with a TermQuery. I like the way that works but I guess what I really need to do is a RangeQuery as well.
I have another large index that has 1.2 million docs. I use a query along with a hit collector for that. I then get the lat/lon for each doc and calc the distance there. I use some radian math to prevent the expensive great circle distance first. I guess this is more expensive than your range query above? I've indexed my docs with lat/lon encoded in a single field comma separated. I still get < 1 second search times but I know there has to be a better way. Don't you have to multiply your lat/lon by 1000 to preserve decimal accuracy and then calc your offset? Maybe it's late and I'm not thinking about this right :) Mark
