Avi Silberschatz's "Database System Concepts: Parallel Databases"
Read this lecture, which covers parallel databases. While you read, be sure to compare and contrast the components available in parallel databases.
Click http://web.archive.org/web/20150501002745/http://www.cse.iitb.ac.in/~sudarsha/db-book/slide-dir/ch21.pdf link to open resource.