Adding perl

Hi All,

I have just finished writing a perl script to process some text data and now I
want to turn it into a function.

createlang fails as follows
# createlang -U postgres plperl MYDB
createlang: language installation failed: ERROR:  could not access file
"$libdir/plperl": No such file or directory

Okay so I find the following
   Note:  Users of source packages must specially enable the
   build of PL/Perl during the installation process. (Refer
   to Section 14.1 for more information.) Users of binary
   packages might find PL/Perl in a separate subpackage.
on the Perl documentation page
http://www.postgresql.org/docs/8.0/interactive/plperl.html

So, does this mean that I need to download v8.0.2 source, recompile and
reinstall?  If so can I do this over the current v8.0.0?

If something breaks can I go back to v8.0.0?

Kind Regards,
Keith