agree John, For a rough geographical search eg within 20k's, even down here in NZ where we have a big difference between a degree of lat and one of long, this seems to be the fastest search ( in sql) Having trouble understanding why mysql does not support a simple radius search.
On Tuesday, April 3, 2007 4:59:27 PM UTC+12, [email protected] wrote: > > If you want a really simple solution and don't mind a "rectangular" > search radius instead of a round one. Just make sure lat,lng are > indexed and write the query like: > > SELECT fish_name WHERE lat > $low_lat AND lat < $high_lat AND lng > > $low_lng AND lng < $high_lng > > This query is fast because it can use the index. If you do a distance > computation in SQL, you have to do it on every row. > > A lazy way to compute the $low_lat,$high_lat, etc. is to just assume 1 > degree ~= 40,000/360 km. > > -John Campbell > > -- You received this message because you are subscribed to the Google Groups "Google Maps API V2" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-maps-api/-/w-kfMflSZ0EJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=en.
