Add a procedural language to a database?

The absolute easiest way to do this is to run createlang from the command line.

First you should be logged in as or be impersonating the postgres user.

You can do this easily on Linux/Unix by using the su command.

# su postgres

Then type the following-

For PLperl or PLperlu:

$ createlang plperl yourdatabase

$ createlang plperlu yourdatabase

For PLpgsql:

$ createlang plpgsql yourdatabase