I have created a couple of PostgreSQL sample databases at
https://github.com/vrajmohan/pgsql-sample-data:
1. The supplier-part-project database from C J Date's book.
2. The Employee sample database from the MySQL project. This db
occupies 300MB and and has ~4 million total rows.
Please let me know if you find this useful.
I tried contributing to http://pgfoundry.org/projects/dbsamples/, but
pgFoundry appears to be down. I spoke to the project admin and we
agreed that it would make sense to migrate the project over to Github.
--Vraj Mohan