The Database behind Facebook

Odds are you are one of the more than 1.3 billion active users of Facebook. If so, you probably know how to "friend" people and post photos, videos, and status updates. What you may not know is that there is a giant database that keeps track of all this information. Here is a partial list of what Facebook's database must track:

• Almost 1 billion objects, such as pages, groups, events, and communities

• More than 30 billion pieces of content, including links, posts, photos, notes, videos, and new stories

• Friend connections among the more than 1.3 billion active users (The average user has well over 100 friends.)

Source: https://newsroom.fb.com/company-info/.

Keeping track of all this information requires a very complex database design, in addition to a robust infrastructure. Facebook uses a variety of tools to create and manage its data, including Apache Cassandra, which manages data across hundreds of servers; Apache Hive, which facilitates summarizing and retrieving data in very large databases; and Scribe, which reliably delivers billions of Facebook messages each day.

While you may never have to deal with databases this large, you will probably have to use databases throughout your work life. Much of the information you will need to access in order to do your job will be stored in relational databases. Relational databases underlie many of the applications discussed throughout this book, including enterprise resource planning, customer relationship management, and supply chain management systems. (Note that Facebook uses other types of database technologies in addition to relational databases.)

Questions

1. Identify the information elements that are part of a Facebook profile.

2. What information do you think Facebook uses to determine what friend suggestions to make?