Database Reference
In-Depth Information
Because of some of the inherent design decisions in RDBMS, it is not always as easy to scale
as some other, more recent possibilities that take the structure of the Web into consideration.
But it's not only the structure of the Web we need to consider, but also its phenomenal growth,
because as more and more data becomes available, we need architectures that allow our organ-
izations to take advantage of this data in near-time to support decision making and to offer new
and more powerful features and capabilities to our customers.
NOTE
It has been said, though it is hard to verify, that the 17th-century English poet John Milton had actually
read every published topic on the face of the earth. Milton knew many languages (he was even learning
Navajo at the time of his death), and given that the total number of published topics at that time was in
the thousands, this would have been possible. The size of the world's data stores have grown somewhat
since then.
We all know the Web is growing. But let's take a moment to consider some numbers from the
IDC research paper “The Expanding Digital Universe.” (The complete paper is available at
ht-
▪ YouTube serves 100 million videos every day.
▪ Chevron accumulates 2TB of data every day.
▪ In 2006, the amount of data on the Internet was approximately 166 exabytes (166EB). In
2010, that number reached nearly 1,000 exabytes. An exabyte is one quintillion bytes, or 1.1
million terabytes. To put this statistic in perspective, 1EB is roughly the equivalent of 50,000
years of DVD-quality video. 166EB is approximately three million times the amount of in-
formation contained in all the topics ever written.
▪ Wal-Mart's database of customer transactions is reputed to have stored 110 terabytes in
2000, recording tens of millions of transactions per day. By 2004, it had grown to half a
petabyte.
▪ The movie Avatarrequired 1PB storage space, or the equivalent of a single MP3 song—if
that MP3 were 32 years long (source:
http://bit.ly/736XCz
).
▪ As of May 2010, Google was provisioning 100,000 Android phones every day, all of which
have Internet access as a foundational service.
▪ In 1998, the number of email accounts was approximately 253 million. By 2010, that num-
ber is closer to 2 billion.
As you can see, there is great variety to the kinds of data that need to be stored, processed, and
queried, and some variety to the businesses that use such data. Consider not only customer data
