You might also consider a trigger to calculate the distance once on insert/update. They you could use an index.
On 6/14/2011 4:53 AM, Simon Slavin wrote: > On 14 Jun 2011, at 12:11pm, Martin.Engelschalk wrote: > >> make sure you have an index on category and distance, like >> >> create index MyIndex on Location (category, distance) > Peter is calculating distance inside his SELECT, but I agree that an index on > (category) is an excellent idea. > > The other thing is that this is a bit like RTREEs. So Peter, you might like > to read > > <http://www.sqlite.org/rtree.html> > > I don't know if it's worth using rtrees in your particular example but you > might find them useful. > > Simon. > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
