Q:

Is it possible to add SSL support after a build is up and running?

I recently tried to upgrade my postgresql from 9.0 to 9.1.
I got to a point where I was able to get both builds to run concurrently (on different ports).
Then I tried copying some settings from the old config file into the new one, and one of the settings was setting SSL to enabled. This by itself is alright, but unfortunately, back when I first built the build, I forgot to configure it with SSL. And as such, I get the following error when I try to start up the server:  FATAL:  SSL is not supported by this build.
So, can I add SSL support to an already built and installed Postgresql? Or, am I going to have to delete stuff, reconfigure the build, remake it and finally re-install it?
Also, could someone tell me how to set it up correctly. For example, at the moment, if I use the psql command in the terminal, it uses the old psql (i.e. the 9.0's psql), and if I want to use of any the new commands (i.e. 9.1's commands), I have to write out a full directory, like this: /usr/local/pgsql/bin/postgres -D /var/lib/postgresql/9.1/main -p 5433. It would also be nice to know how to have postgresql start up on boot time.
Thanks a lot for the help, I know my questions are a bit simplistic, but I am still getting used to linux development and administration. 

A:

In order to add SSL support to your installation, you need to rerun the configure, make, make install sequence with the appropriate options.  But you don't have to delete anything.  Just install the new binaries over the old ones and restart the server.

