The .sql is a plain text SQL backup that should be restored with psql.

It consists of the census and staging schemas. As well as some other minor tables Some of these are built as part of exercises in the book.

To restore:

CREATE DATABASE postgresql_book;
\connect postgresql_book
\i postgresql_book.sql

IMDB movies list comes from ftp://ftp.fu-berlin.de/pub/misc/movies/database/movies.list.gz refer to copyright details in http://www.imdb.com/interfaces Information courtesy of IMDb (http://www.imdb.com). Used with permission.