PREFIX is when you're built your own complete installation of Perl and installed it there. LIB is probably what the questioner wants.

You have the steps incomplete, though:

mkdir ~/src
cd ~/src
(download DBI-1.blahblah.tar.gz)
tar xzf DBI-1.blahblah.tar.gz
cd DBI-1.blahblahblah
perl Makefile.PL LIB=~/myperl
make
make test
make install
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I'm keeping the source code to the DBI module in one place (~/src) and the installed version in another (~/myperl). Always a good idea.

Then put this at the top of your program that uses the DBI module:

use lib "/usr/home/sz/myperl";
use DBI;
[download]

and it should load the DBI library from that directory.

If you have different versions of Perl all over the place, you might have to say:

/pkg/perl5/plus/bin/perl Makefile.PL LIB=~/myperl
[download]

To specify which version of Perl the module is being built for. This would be the same version of Perl that you put at the top of your programs:

#!/pkg/perl5plus/bin/perl -w

Hope this helps you!

Nat