Database Reference
In-Depth Information
Approximate Value
for Reference
Name
Symbol
Actual Value
Byte
8 bits [Store one character]
About 10
3
2
10
= 1,024 bytes
Kilobyte
KB
About 10
6
2
20
= 1,024 KB
Megabyte
MB
About 10
9
2
30
= 1,024 MB
Gigabyte
GB
About 10
12
2
40
= 1,024 GB
Terabyte
TB
About 10
15
2
50
= 1,024 TB
Petabyte
PB
About 10
18
2
60
= 1,024 PB
Exabyte
EB
About 10
21
2
70
= 1,024 EB
Zettabyte
ZB
Figure 12-1
Storage Capacity Terms
About 10
24
2
80
= 1,024 ZB
Yottabyte
YB
datasets generated by Web applications such as search tools (for example,
Google and Bing) and Web 2.0 social networks (for example, Facebook,
LinkedIn, and Twitter). Although these new and very visible Web applications
are highlighting the problems of dealing with large datasets, these problems
were already present in other areas, such as scientific research and busi-
ness operations.
1
Just how big is Big Data? Figure 12-1 defines some commonly used
terms for data storage capacity. Note that computer storage is calculated
based on binary numbers (base 2), not the usual decimal (base 10) numbers
we are more familiar with. Therefore, a kilobyte is 1,024 bytes instead of the
1,000 bytes we would otherwise expect.
If we consider the desktop and notebook computers generally in use
as this topic is being written (early 2013), a quick check online of available
computers shows notebooks being sold with hard drives up to 750 MB in
capacity, whereas some desktops are available with 2 TB. That is just for
one computer. Facebook is reported to handle more than 40 billion photos
in its database.
2
If a typical digital photo is about 2 MB is size, that would
require about 9.3 PB of storage!
As another measure of Big Data, Amazon.com reported that on
November 29, 2010, orders for 13.7 million products were placed. This is
an average of 158 product orders per second.
3
Amazon.com also reported
that, on the peak day of the 2010 holiday season, its worldwide fulfillment
network shipped more than 9 million items to 178 countries. This volume of
1
For more information, see the Wikipedia article on Big Data at
http://en.wikipedia.org/wiki/Big_data
.
2
Wikipedia article on Big Data at
http://en.wikipedia.org/wiki/Big_data
(accessed February 2013).
3
Amazon.com, “Third-Generation Kindle Now the Bestselling Product of All Time on Amazon Worldwide.”
News release, December 27, 2010. Available at
http://phx.corporate-ir.net/phoenix.zhtml?c=176060&p=irol-
newsArticle&ID=1510745&highlight=
(accessed February 2013).
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