Re: Better search algorithm?

newsgroups_at_makethematch.com (Jason Chancellor) wrote in message news:<a19c9a2e.0107231155.7f3c4dd8_at_posting.google.com>...
> Hello, I am working on a project which is beginning to show some
> performance issues, and I have been trying some different techniques
> with no better results....so I thought I would ask around for some
> advice.

[ snip ]

> So here I am, totally out of ideas... Can anyone think of a better
> way to perform the search I am trying to do, or can anyone point me
> to a book or a URL of some info that might be of help?

 Use a DBMS that implements a spatial access method. PostgresSQL, for  example, supports a R-Tree that reduces your query to something like:

   SELECT H1.Stuff
     FROM Lonely_Hearts H1, Lonely_Hearts H2     WHERE H1.Still_Lonely = 'TRUE'

      AND Within ( H2.Location, Circle ( H1.Location, 0.3))
      AND H1.Chemistry MATCHES H2.Chemistry;

   This kind of query will perform a lot better than the nested loop operation  you're probably doing now. You might also Google (R-Tree, Database) for other  DBMS products that implement a spatial access method. Plus it will give you a  segue into the "location based services" when the location is to be found on  the cell phone and "zip code" ain't gonna cut it.

   It might come as a shock, but DBMS products are not inter-changeable  commodities. They possess overlapping, but still quite different functionality.

   Hope this helps.

  KR  

         Pb Received on Tue Jul 24 2001 - 07:25:44 CEST