Database Reference
In-Depth Information
23. Placing the business functions on the client causes a client maintenance problem. Whenever pro-
grammers change the business functions, they must place the updated business functions on
every client. Placing the business functions on the server causes a scalability problem and might
cause the server to become a bottleneck and degrade the system
s responsiveness to clients.
25. Scalability is the ability of a computer system to continue to function well even as utilization of
the system increases.
27. Compared to a file server, the advantages of a client/server architecture are: lower network traffic;
improved processing distribution; thinner clients; greater processing transparency; increased net-
work, hardware, and software transparency; improved security; decreased costs; and increased
scalability.
29. Dynamic Web pages are Web pages whose content changes in response to the different inputs and
choices made by Web clients. You can use client-side extensions embedded in HTML documents
or contained in separate files, or you can use server-side extensions usually contained in sepa-
rately executed programs.
31. XML (Extensible Markup Language) is a metalanguage derived from a restricted subset of SGML
and is designed for the exchange of data on the Web. Using XML, you can create text documents
that follow simple, specific rules for their content, and you can define new tags that define the
data in the document and the structure of the data, so that programs running on any platform can
interpret and process the document.
33. XSL Transformations (XSLT) define the rules to process an XML document and change it into
another document; this other document could be another XML document, an XSL document, an
HTML or XHTML document, or most any other type of document.
35. A data warehouse is a subject-oriented, time-variant, nonvolatile collection of data in support of
management
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s decision-making process.
37. A fact table in a data warehouse consists of rows that contain consolidated and summarized data.
39. Using OLAP software, users slice and dice data, drill down data, and roll up data.
41. You can measure OLAP systems against the following 12 rules: users should be able to view data
in a multidimensional way; users should not have to know they are using a multidimensional
database; users should perceive data as a single user view; the size and complexity of the ware-
house should not affect reporting performance; the server portion of the OLAP software should
allow the use of different types of clients; each data dimension should have the same structural
and operational capabilities; missing data should be handled correctly and efficiently; OLAP
should provide secure, concurrent access; users should be able to perform the same operations
across any number of dimensions; users should not need to use special interfaces to make their
requests; users should be able to report data results any way they want; and OLAP software
should allow at least 15 data dimensions and an unlimited number of summary levels.
43. A domain is the set of values that are permitted for an attribute.
45. A method is an action defined for an object. A message is a request to execute a method. To exe-
cute the steps in a method, you must send a message to the object.
47. The Unified Modeling Language (UML) is an approach you can use to model the various aspects of
software development for object-oriented systems.
49. A visibility symbol in UML indicates whether other classes can view or update the value in an
attribute in a class.
51. Generalization is the relationship between a superclass and a subclass.
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