Database Reference
In-Depth Information
A typical data warehouse data structure is a star schema consisting of a central fact table surrounded by
dimension tables.
Users perceive the data in a data warehouse as a multidimensional database in the shape of a data cube.
OLAP software lets users slice and dice data, drill down data, and roll up data.
Data mining consists of uncovering new knowledge, patterns, trends, and rules from the data stored in a
data warehouse.
E. F. Codd presented 12 rules that serve as a benchmark against which you can measure OLAP systems.
These rules are multidimensional conceptual view; transparency; accessibility; consistent reporting perfor-
mance; client/server architecture; generic dimensionality; dynamic sparse matrix handling; multiuser sup-
port; unrestricted, cross-dimensional operations; intuitive data manipulation; flexible reporting; and unlimited
dimensions and aggregation levels.
Object-oriented DBMSs deal with data as objects. An object is a set of related attributes along with the
actions that are associated with the set of attributes. An OODBMS is a database management system in
which data and the actions that operate on the data are encapsulated into objects. A domain is the set of
values that are permitted for an attribute. The term class refers to the general structure, and the term
object refers to a specific occurrence of a class. Methods are the actions defined for a class, and a mes-
sage is a request to execute a method. A subclass inherits the structure and methods of its superclass.
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The UML is an approach to model all the various aspects of software development for object-oriented sys-
tems. The class diagram represents the design of an object-oriented database. Relationships are called
associations, and visibility symbols indicate whether other classes can view or change the value in an attri-
bute. Multiplicity indicates the number of objects that can be related to an individual object at the other end
of the relationship. Generalization is the relationship between a superclass and a subclass.
Properties that serve as a benchmark against which you can measure object-oriented systems are com-
plex objects, object identity, encapsulation, information hiding, types or classes, inheritance, late binding,
computational completeness, extensibility, persistence, performance, concurrent update support, recovery
support, and query facility.
Key Terms
access delay
Apache HTTP Server
application servers
associations
back-end machine
back-end processor
binary large objects (BLOBs)
binding
business to business (B2B)
class
class diagram
client-side extensions
client-side scripts
client/server
clients
communications network
cookies
coordinator
data cube
data fragmentation
data mining
data warehouse
database server
dimension table
distributed database
distributed database management system (DDBMS)
Document Type Definition (DTD)
domain
drill down
dynamic Web pages
electronic commerce (e-commerce)
encapsulated
extensible
Extensible Hypertext Markup Language (XHTML)
Extensible Markup Language (XML)
Extensible Stylesheet Language (XSL)
fact table
fat client
file server
fragmentation transparency
