On Nov 20, 2009, at 3:15 AM, Oliver Beattie wrote: > Hi all, > > I'm a relative newcomer to Solr, and I'm trying to use it in a project > of mine. I need to do a function query (I believe) to filter the > results so they are within a certain distance of a point. For this, I > understand I should use something like sqedist or hsin, and from the > documentation on the FunctionQuery page, I believe that the function > is executed on every "row" (or "record", not sure what the proper term > for this is). So, my question is threefold really; are those functions > the ones I should be using to perform a search where distance is one > of the criteria (there are others),
Short answer: yes. Long answer: I just committed those functions this week. I believe they are good, but feedback is encouraged. > and if so, does Solr execute the > query on every row (and again, if so, is there any way of preventing > this [like subqueries, though I know they're not supported])? You can use the frange capability to filter first. See http://www.lucidimagination.com/blog/tag/frange/ Here's an example from a soon to be published article I'm writing: http://localhost:8983/solr/select/?q=*:*&fq={!frange l=0 u=400}hsin(0.57, -1.3, lat_rad, lon_rad, 3963.205) This should filter out all documents that are beyond 400 miles in distance from that point on a sphere (specified in radians, see also the rads() method) > > Sorry if this is a little confusing… any help would be greatly appreciated :) No worries, a lot of this spatial stuff is still being ironed out. See https://issues.apache.org/jira/browse/SOLR-773 for the issue that is tracking all of the related issues. The pieces are starting to come together and I'm pretty excited about it b/c not only will it bring native spatial support to Solr, it will also give Solr some exciting new general capabilities (sort by function, pseudo-fields, facet by function, etc.)
