Disk usage - Mailing list pgsql-novice

Hi,

I really don't understand the part of the docmentation about
determining the disk usage of a database (section 24.1).

The bit that puzzles me is:

"contrib/dbsize loads functions into your database that allow you to
find the size of a table or database from inside psqlwithout the need
for VACUUM or ANALYZE.

You can also use contrib/oid2name to show disk usage. See
README.oid2name in that directory for examples. It includes a script
that shows disk usage for each database."

What is contrib? I am shure it's a directory, but where is it?

Thanks,
Martin.