> Does postgresql have functions to calculate the distance between two
> sets of longitude and latitude.
>
You're looking for the earthdistance contrib module. With most Linux distros
it's installed under /usr/share/postgresql/8.xx/contrib
You may have to install a "postgresql-contrib" package depending on your
distro.
Typing "locate earthdistance.sql" should reveal the location if it's available
already. To activate you'd just do a "pgsql [database] <
/whereever/earthdistance.sql"
HTH
Uwe
