> Where can I find instructions to install these functions in my 7.4 version?
> I am awaret hat they are in the contrib. folder but I have never installed
> functions from the contrib folder. Thanks in advance.
From postgresql-7.4.2/contrib/README:
Each subdirectory contains a README file with information about the
module. Most items can be built with `gmake all' and installed with
`gmake install' in the usual fashion, after you have run the `configure'
script in the top-level directory. Some directories supply new
user-defined functions, operators, or types. After you have installed
the files you need to register the new entities in the database system
by running the commands in the supplied .sql file. For example,
$ psql -d dbname -f module.sql
See the PostgreSQL documentation for more information about this
procedure.
good luck!