"Stuart Grimshaw" <stuart(dot)grimshaw(at)gmail(dot)com> writes:
> I've installed the postgresql-contrib8.1 deb package to get at the
> earthdistance function, but it doesn't seem to be recognised, even
> after a restart of the server.
> Is there a final step I need to take after using apt-get to install?
Yeah, you have to run the SQL script included in the module to define
its functions within a particular database. Look for earthdistance.sql
among the files installed by the .deb (it's likely under /usr/share).
regards, tom lane