Geography Reference
In-Depth Information
PRINCIPLES OF GI AND CARTOGRAPHY
Databases, Cartography, and Geographic Information
Chapter 6
Databases, Cartography,
and Geographic Information
Geographic representation and cartographic representation abstract obser-
vations and measurements about things and events in the world. These
abstractions are only useful if they are saved and stored in formats that
enable access to them. Databases provide the most common computerized
means to save and store data, and they also use encoding and organization to
access, manage, and analyze the data. Databases follow various principles to
create a structure that is extremely f lexible for the needs of geographic rep-
resentation and cartographic representation; however the structure is one
that can be daunting in its complexity. Databases are fundamental to system-
atizing representations of the world. At the same time, the use of databases
also opens new possibilities for creating many different representations.
Geographic information created years earlier now can be accessed and com-
bined with other geographic information if the databases are accessible.
This chapter focuses on providing a concise overview of relational data-
base technologies as they are used for GIS maps and geographic informa-
tion. It introduces the basic principles of relational databases, forms of stor-
age, and applications. The objective is the presentation of a solid overview of
database technology in terms of issues for geographic representation and
cartographic representation, including data modeling.
What Is a Database?
A
database
is a collection of data stored in a structured format using a com-
puter. A database can be thought of as a table, but the distinction is that the
table is just one way (of many) to represent the database.
The first databases were flat-file databases: computer files of text with
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