[Rails] Some questions about Ferret

[Carl Lerche]

Hello,

I'm trying to implement a search feature in a project I'm working on.  
Here is the gist of it. The project is basically a classified site  
which allows people to post a classified ad in a category and specify  
the zip code. I would like to let people search classifieds that are  
local to them (defined as within 15 miles of their zip). So, would it  
be possible to use Ferret to provide searching of the classifieds on  
a local basis? Before, with mysql fulltext search I could do a join  
between the zip table and the classifieds table, but I found the  
results to not be great.

Also, it seems that ferret stores the index file locally. What  
happens if I add extra web servers and use load balancing? What  
happens to the index in this case?

Thanks,
Carl