How Google searches 30 trillion web pages, 100 billion times a month

Search starts, of course, with crawling and indexing, and Google says that the web now has 30 trillion unique individual pages. That up an astonishing 30 times in five years: Google reported in 2008 that the web had just one trillion pages. Google says that it stores information about those 30 trillion pages in the Google Index, which is now at 100 million gigabytes.